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Friday, December 27, 2013
SolderSmoke Podcast #157: Peter Parker on Phasing Rigs
SolderSmoke Podcast #157 is available for download.
http://soldersmoke.com/soldersmoke157.mp3
December 27, 2013
-- Santa Report: Rigol Scope at SolderSmoke HQ. Kites at VK3YE.
-- Project updates: Bill's BITX 40/20 build.
-- Peter finishing up BITX40 (in a big box)
-- BITX 17 (5 watts SSB) works JA, ZD7, ZS!
-- The mystery, elegance, and gentleness of phasing SSB
-- Phasing explained in 1970 ARRL SSB book
-- Phasing SSB: From Hallicrafters HT-37 to SDR
-- The SP5AHT Phasing Rig
-- I & Q for you: The Binaural Experience
-- Direct Conversion receivers and Software Defined Radios
-- Simple DC receivers plugging into sound cards
-- The joy of receiver building
-- 144 MHz aircraft bounce (Melbourne to Sydney)
-- VHF Across The Great Australian Bight
HAPPY NEW YEAR TO ALL!
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Wednesday, December 25, 2013
Santa Arrives at SolderSmoke HQ! Rigol and Black&Decker
Santa Claus obviously heard my distress call when the TEK 465 gave up the ghost. This morning it was replaced by a RIGOL digital scope. I'm going through the tutorials. Wow, lots of features. A Black&Decker jig saw also arrived -- this will help in my cabinetry efforts.
Last night just before dinner I talked to Kiyo, JH1MDJ, in Tokyo on 17 meter SSB with the 5 watt BITX. I kind of broke through a small pile-up and we then had one of those "please repeat your power level... I can't believe that is 5 watts to a dipole" conversations.
Happy Holidays to all!
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Labels:
Japan,
oscilloscope,
test gear,
workbench
Saturday, December 21, 2013
How they took the iconic Apollo 8 Earthrise Photo (Amazing Video)
I was ten years old and totally obsessed with the space program. This video brought back a lot of the magic. Wow. You really have to see this one.
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Labels:
photography,
space program,
video
Where to send all those LM386 chips: Make them BEAM robot brains!
Over in the BITX20 yahoo group there have been some comments about the shortcomings of the widely used LM386 audio amplifier chip. Many people don't like it because it is noisy. I don't like it because it is a chip. (In my BITX rigs I have replaced it with a simple discrete component audio amplifier.) So this morning I was pleased to find this video on the Maker blog that presents a very good use for all those LM386 devices: We can turn them into robot brains!
Make's video and web page on this project are both very good. One paragraph in the page kind of captures the reasons I dislike the LM386:
How It Works
The core of the “Herbie” circuit is the LM386 power amplifier chip. To simplify a bit, we can think of the chip as a “black box” with inputs and outputs that respond in predictable ways, and don’t have to completely understand what’s going on inside.http://makezine.com/projects/sunbeam-seeker-bot/
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Friday, December 20, 2013
Christmas Eve Fessenden Memorial Broadcast on 486 KHz
Imagine it is Christmas Eve, 1906 and you are on the air, listening to the harsh buzz of Ol' Spark Morse Code. Suddenly, in the headphones you hear a human voice and music.
Brian Justin has set up an experimental station that recaptures that magical "birth of radio telephony" moment. He will be on the air this Christmas Eve, Christmas Day and New Year's day. Here is what W4DEX heard during last year's event:
http://www.w4dex.com/500khz/wf9xih/wf9xih_24dec11.mp3
Experimenter to Honor Early Wireless Pioneers with Longwave Transmissions
As he has over the past several years, Brian Justin, WA1ZMS/4 -- as experimental station WG2XFQ -- will transmit voice and music on 486 kHz on Christmas Eve and Christmas Day and again on New Year's Eve and New Year's Day. Transmissions will begin at 0001 UTC and end at 2359 UTC. Justin, who may be better known for his microwave exploits on ham radio, will use an AM audio loop modulating his vintage-style, homebrew transmitter to honor Reginald Fessenden's Christmas Eve 1906 AM voice transmission.
"While his original transmissions used a set of carbon microphones in the antenna lead to modulate the signal," Justin explained, "WG2XFQ will be utilizing true Heising modulation in honor of Raymond Heising, who developed this early form of amplitude modulation during World War I.Justin constructed his 5 W master oscillator power amplifier (MOPA) transmitter using 1920s-vintage components. He said a modern 500 W FET linear amplifier allows him to meet his WG2XFQ ERP limit of 20 W. An RF engineer, Justin collects pre-1920 wireless gear and has a World War I Heising-modulated aircraft transmitter he's planning to restore. Justin was an active participant in the ARRL's WD2XSH 600 meter experimental project.
(From the ARRL Newsletter)
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Brian Justin has set up an experimental station that recaptures that magical "birth of radio telephony" moment. He will be on the air this Christmas Eve, Christmas Day and New Year's day. Here is what W4DEX heard during last year's event:
http://www.w4dex.com/500khz/wf9xih/wf9xih_24dec11.mp3
Experimenter to Honor Early Wireless Pioneers with Longwave Transmissions
Fessenden |
WA1ZMS constructed his MOPA transmitter from 1920s-vintage components. [Brian Justin, WA1ZMS, photo] |
(From the ARRL Newsletter)
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Labels:
Old radio,
radio history
Wednesday, December 18, 2013
BITX 2040 Build Update #2: Of Spreadsheets and VFOs
I continue to tweak the capacitors in my new BITX 20/40 VFO (scroll down to see it). On Sunday I added a little relay that will switch in some additional capacitance to move the VFO about 500 kHz. Without the additional cap, the VFO will be on frequencies suitable for 40 meters -- with the additional cap it will be on frequencies needed for tuning 20 meters.
I calculated that I'd need an additional 220 pf to make this shift ( I later went with 100 pf). In went the needed cap and relay. It worked. But there was a problem: On 40 I had the desired 175 kHz frequency range. But I found that with this arrangement on 20 I could only cover 95 kHz. Obviously my variable air cap with 44 pf in series was being "diluted" by the additional 220 pf being switched in by the relay -- with the additional capacitance, the change in total capacitance produced by the variable cap (with series cap) was smaller in the 20 meter range than it was in the 40 meter range.
Clearly, one solution was to play with the value of the cap that I had in series with the variable cap -- increasing it would increase the freq spread (both on 40 and 20). But how much should I increase it?
By this point I was getting tired of all the manual calculations. Time for a spreadsheet! I created one, and threw in the values of all the caps and of the coil, and the resonant frequency formula. I set it up to display and the resulting freq coverage.
The freq ranges in the actual ham bands is a bit off -- there may be some stray capacitance and inductance in the circuit that is not being captured in my numbers. But the important thing was the spread. The spreadsheet allowed me to see that with a 100 pf cap switched in by the relay and a 74 pf cap in series with the variable, I could cover 180 kHz on 40 and 123 kHz on 20. That's OK. This little exercise shows the usefulness of spreadsheets in dealing with this kind of calculation.
You can see my spreadsheet here:
https://docs.google.com/spreadsheet/ccc?key=0Ak4BJL1-oWiJdElieDY5Y2xVWUtSNDl0anRYLVBBeGc&usp=drive_web#gid=0
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I calculated that I'd need an additional 220 pf to make this shift ( I later went with 100 pf). In went the needed cap and relay. It worked. But there was a problem: On 40 I had the desired 175 kHz frequency range. But I found that with this arrangement on 20 I could only cover 95 kHz. Obviously my variable air cap with 44 pf in series was being "diluted" by the additional 220 pf being switched in by the relay -- with the additional capacitance, the change in total capacitance produced by the variable cap (with series cap) was smaller in the 20 meter range than it was in the 40 meter range.
Clearly, one solution was to play with the value of the cap that I had in series with the variable cap -- increasing it would increase the freq spread (both on 40 and 20). But how much should I increase it?
By this point I was getting tired of all the manual calculations. Time for a spreadsheet! I created one, and threw in the values of all the caps and of the coil, and the resonant frequency formula. I set it up to display and the resulting freq coverage.
The freq ranges in the actual ham bands is a bit off -- there may be some stray capacitance and inductance in the circuit that is not being captured in my numbers. But the important thing was the spread. The spreadsheet allowed me to see that with a 100 pf cap switched in by the relay and a 74 pf cap in series with the variable, I could cover 180 kHz on 40 and 123 kHz on 20. That's OK. This little exercise shows the usefulness of spreadsheets in dealing with this kind of calculation.
You can see my spreadsheet here:
https://docs.google.com/spreadsheet/ccc?key=0Ak4BJL1-oWiJdElieDY5Y2xVWUtSNDl0anRYLVBBeGc&usp=drive_web#gid=0
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Sunday, December 15, 2013
20/40 BITX Build Update #1: VFO Success
I've started construction on my second BITX transceiver, this one for 20 and 40 meters. As with the previous rig, I decided to take the VFO first, but this time I pledged not to surrender, not to wimp out with a VXO or (worse!) a DDS. No, this time it would be a real LC VFO.
I took seriously all the admonitions in the tech literature about the fickle permeability of ferrite and iron powder, so this time I used an old-fashioned air-core coil. It is wound around a cardboard tube. The tube was previously the bottom portion of a coat-hanger from the dry cleaner. I wound 40 or so turns on this core, then measured the inductance: 5.6 uH -- that looked about right.
For the oscillator stage I used a Colpitts circuit very similar to the one in the original BITX schematic (but I am hoping I won't need the varactor diode fine tune mechanism). I had on hand a nice Heathkit 19-146 pf variable cap with an internal 4:1 reduction drive. Not wanting to pluck rotor places out of this beautiful part, I had to calculate the series capacitance that would yield a frequency spread of about 175 kHz. It turned out to be 40 pf. Then I had to figure out how much capacitance to put in parallel with the variable. Well, it all ended up like this:
There was a bit of trial and error in the process of getting the VFO to cover the desired range. A big help in all this was an on-line reactance calculator. I found this one to be very useful:
http://www.1728.org/resfreq.htm
I found that the VFO is more stable if I reduce the voltage from 12 volts down to about 8. Also, I found that when evaluating the stability, it is better (psychologically!) just to use a stable superhet receiver instead of the frequency counter. The counter may appear to be jumping around a lot, especially if the signal you are monitoring is not very strong. Just listening to it at zero beat on the superhet is very reassuring.
I followed the Colpitts oscillator with the FET buffer and two stage BJT amplifiers from page 50 of Doug DeMaw's QRP Notebook (page 50). I now have the requisite 7 dbm signal. And it appears to be quite stable.
I plan using this with an 11 MHz IF, with the VFO running at around 3.875--3.700 for 40 meters and 3.175 -- 3.355 for 20. I plan to use a small relay to switch in some additional capacitance to move the VFO down to the range for 20 meters.
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Saturday, December 14, 2013
University of Twente's Online Receiver
Wow, I played with this on-line SDR receiver a few years ago and thought it was fantastic. It is now even better. I'm sitting here listening to 40 meters in the Netherlands. Great stuff. Check it out. It is really amazing:
http://websdr.ewi.utwente.nl:8901/
Thanks to Bob, KD4EBM for letting me know about the updates.
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Labels:
Netherlands.,
SDR,
web sites
Friday, December 13, 2013
Circular Polarity and The Water Wheel in Dale's Moonbounce Amplifier
Bill:
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I'll attach some
pix of the feedhorn and LNA for you.
The importance
of circular feeds is that as a linear wave passes through the ionosphere, it
undergoes Faraday rotation. So it may arrive at the station you are talking to
having been twisted 90 degrees. This is a slow progressing process and on all
bands except 23cM, may cause EU for example to be locked out for hours at a time
for linear stations.
With circular
polarity, Faraday is a non issue. The feedhorn almost all of us use is a VE4MA
that has separate TX and RX probes. The circular polarity is synthesized as the
linear wave propagates down the circular waveguide and encounters sets of
capacity stubs. The exact opposite occurs for waves entering the waveguide. The
result is we get CW and CCW without having to use any relays (loss) and phasing
lines (loss).
My LNA has a
noise figure of under 0.24dB and uniquely connects to a protection relay with no
cable or adapters (loss).
The position of
the feedhorn and its scalar ring is tediously adjusted by measuring
the difference between sun noise and cold sky. W4SC developed a very accurate
and repeatable process that uses an SDR RX for this.
I use a
modified C band satellite drive system known as a polar mount so I only need one motor drive to track the moon.
Anyway, hearing
my own echoes off the moon was and still is the highlight of my amateur
career.
The photos are
the feedhorn + LNA, My first water cooled 500W tube amp, my previous 400W solid
state amp (mounts right at the dish). My current design is 600W solid state and
will also mount at the dish.
BTW, that little
circle in the middle of the tube amp is a paddle wheel that turns as long as
water is flowing. A tachometer on the wheel sounds an alarm and shuts down plate
voltages should the wheel stop turning.
I'll keep you
up to date on my BB RX progress- thank you again Bill.
Dale W4OP
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Labels:
amplifier theory,
EME,
moonbounce
Wednesday, December 11, 2013
The NASA Juno Fly-by "Hams say HI to Juno" Video (very nice)
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
Jupiter,
satellites,
space program,
video
Tuesday, December 10, 2013
The QRP Mojo Ceremony
More from Lobstercon (from N2HTT):
http://n2htt.net/2013/11/24/there-are-lobsters-in-the-woods/
And thanks to Pete, VE2XPL, for alerting me to all this.
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Labels:
DeMaw--Doug,
video
Sunday, December 8, 2013
Need help with part construction...
Please take a look and see if you can help me figure out how to make this thing. The diagram is eschpecially illuminating.
THE
DIE-CAST DROP-FORGED PLASTIC
TRICHOTOMETRIC
INDICATOR-SUPPORT
Inquiries concerning the mounting of
the Trichotometric Indicator
Support indicate that some difficulty
is being experienced with the
brackets which attach the support. As
an aid toward fabricating the
support brackets, the accompanying
illustration is provided to show
the type of material as well as the
dimensional data needed. It will
be noted that in attaching the bracket
to the support a special ambi-
melical hexnut is used. The
application of this nut is unique in that
any attempt to remove it in the
conventional manner only tightens it.
Because of this design, the nut must
be fully screwed on before it can
be screwed off.
DRAWN BY
|
FRED SPOON
|
SCALE ¼”=1 MILE
|
NO. 43906
|
FILE – BAR NONE
|
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On the Wavelength of Santa's Sled (with a nod to FA Wilson)
About a year ago, David, M0VTG, was reading "From Atoms to Amperes" by FA Wilson. His thoughts turned to a seasonal application of Wilson's lessons.... Thanks David!
WAVELENGTH OF SANTA AND HIS SLEIGH
We're going to need to know the
following:
Total mass of the sleigh, reindeer,
Santa and his presents, and the speed at which the sleigh travels.
Assuming that the sleigh travels relatively close to the surface of
the earth, the mass can be regarded as the same as the weight. Now
assume each reindeer weighs 100 kg. Traditionally there are nine of
them so total mass of the reindeer is 900kg. Say the sleigh also
weighs 500kg and Santa and his presents weigh 400kg; then the total
mass is 1800kg. To get round all the children who believe in him in
one night would mean him travelling at a speed of say 1000kph (277.8
m/s). (Note that scientific notation for numbers used is that used
on some calculators)
So mass (m) is 1800kg
velocity (v) is 1000kph (notice
the not so subtle change from a scalar quantity to a vector
quantity).
Max Plank came up with a formula: E
= hf relates Energy to frequency
using h (Plank's
constant = 6.626 E-34 Joule seconds).
Albert
Einstien (as everyone knows) says that E = mc2
(where c is the velocity of light).
So it
follows that hf = mc2
and
therefore, m = hf/c2.
The
momentum of a photon (p) is
defined as mass x velocity or p = mv and
as every radio amateur knows, wavelength (λ)
is the velocity of light divided by frequency or λ = c/f
(or f/c = 1/ λ).
So mv
= hf/c2 x
c (velocity of a photon is c
don't forget); so p =
hf/c
Since
f/c =1/ λ, then p =
h/λ i.e. λ =h/p
Also
since p = mv then λ
= h/mv (This expression is known
as the de Broglie wavelength - Louis Victor de Broglie)
Notice that the
velocity of light does not directly feature is the expression. We
can, therefore use it the calculate the wavelength of anything!
So the wavelength
of Santa's sleigh is Plank's constant divided by the mass times the
velocity or
λ = 6.626
E-34 J s / (1800 kg x 277.8 m/s) which equals 1.325 E-39 m - an
unbelievably small number! Make up you own mass and velocity for the
sleigh if like.
I
defy NORAD to track such a short wavelength.
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Saturday, December 7, 2013
"Snort Rosin" Seal of Approval for "Ferrari-esque" Italian Wire Cutters
Hi Bill,
It's always nice to find something high-quality and inexpensive and today it happened to me so I thought I'd share my good fortune.
Having been in the professional radio repair business for 40 years (retired 2012), I very much appreciate quality hand tools. On my bench at home I have an expensive pair of Lindstrom wire cutters but in the field I generally resorted to cheaper, not so high-quality tools (in case of inadvertent loss). The problem at home is it seems like every time I need to grab my Lindstroms, they're not where I'm at so I've been on the lookout for a spare pair or two of quality cutters. Well, today in the Fry's Electronic newspaper flyer I saw an ad. for Hakko brand wire cutters on sale for $2.99, regularly $4.99, a 40% saving. Me being, shall we say, "thrifty", this immediately got my attention. I know Hakko markets some very good soldering related equipment, however until today I had no experience with their line of hand tools.
So, between some appointments this morning I stopped at our local Fry's store and checked out the cutters. I was expecting to find something typically cheap and made in China so imagine my surprise at discovering they are made in Italy! The part # of this particular tool is CHP-170 and is mfg. by the CHP Tools division of Hakko. The hand grips are palm-fitting and very comfortable with thumb and forefinger rests at the top of each for tool manipulation. The design is what I would call "Ferrari-esque"; bright red with black accents. Very pleasing to the eye. Turns out that The metal parts are high grade tool steel and Parkerized for low reflectivity and high wear and corrosion resistance. What impressed me the most is the cutting surfaces; they mate perfectly. So many inexpensive cutters have lousy mating surfaces, these don't. With the cutting edges 'closed', shining a high-intensity light on one side results in -no- light 'leaking' by the mated edges. That's first-class machining!
IMO, even at the typical price of $5 or so, these cutters are a bargain, especially considering the quality (how does one say, "it is very good!" in Italian?). So, if you or anyone you know is in the market for some great wire cutters, tell them that the Hakko CHP-170 has the "Snort Rosin" seal of approval, HA!
73.......Steve Smith WB6TNL
http://www.amazon.com/Hakko-CHP-170-Maximum-Cutting-Capacity/dp/B00FZPDG1K
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Labels:
Smith--Steve,
workbench
Friday, December 6, 2013
"The Amateur Scientist" by C.L. Stong (FREE!)
This great book is available on-line: You guys will really like it:
https://archive.org/details/TheAmateurScientist
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
https://archive.org/details/TheAmateurScientist
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
books
Renaissance Man Illustrator for Scientific American
C.L. Stong wrote the "Amateur Scientist" column for Scientific American for many years. When I was a boy, my mom saved up to buy me the anthology of Strong's columns. It had a big impression on me -- I still have a copy on my shelf. I never gave much thought to the illustrations, but I now realize that they were responsible for much of the impact that that book had on me. The cloud chamber drawing was one of my favorites. Note the use of peanut-butter jars. Yea!
This morning an article on the Maker blog focused on the genius who did all those wonderful drawings: Roger Hayward (I wonder if there is any relation to Wes and Roger -- all three are from Oregon and all three are technical geniuses.)
I found this very nice web site about Roger Hayward: http://scarc.library.oregonstate.edu/omeka/exhibits/show/hayward/introduction/introduction/
There are great illustrations in many places. For the Scientific American drawings go to the 1960s section.
And check out this one:
From: http://scarc.library.oregonstate.edu/omeka/items/show/4456
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
books,
Knack Stories
Thursday, December 5, 2013
W4OP -- Earth-Moon-Earth and Another Barebones Superhet
Years ago I bought a Barebones Superhet from Dale Parfitt on E-bay. Several years after that, having forgotten who I bought it from, I was asking questions about how to get it working on 17 meters. Dale jumped in with some very helpful e-mails. It took us both a while to realize that I was working on the receiver that he had built. Dale is active in a really wide range of ham radio activities, everything from QRP to EME. Check out his homebrew projects here (I really like his Solid State Drake 2-B!) http://www.parelectronics.com/par-homebrew-projects.php
And his vintage projects here: http://www.parelectronics.com/vintage-radio-restoration.php
And here's what Dale has been doing with the Moon (that's his 15 foot dish in the picture):
And his vintage projects here: http://www.parelectronics.com/vintage-radio-restoration.php
And here's what Dale has been doing with the Moon (that's his 15 foot dish in the picture):
Hi Bill,
I thought of you today when I won a Bare Bones Barbados RX on
eBay for $5. I am going to team it with a DDS VFO and a matching
TX.Some parts are apparently missing, but i have a huge junk box
and also know how to order from Mouser should the junk box fail me.
Right now I am putting my solid state 650W 1296MHz EME amp ,
Power Supply, meters etc. in its waterproof cabinet so I can mount it right at the dish
and not incur any feedline losses.
1296 is probably the best EME band. Power is getting easier and
easier to acquire (although solid state is around $5/watt), dishes are fairly
easy to acquire or build and perhaps most importantly, we all use circular
polarity feeds with no relays/hybrids. Activity weekend can sound like 20M, with
a number of stations just ragchewing on CW and SSB.
73,
Dale W4OPfor PAR Electronics, Inc.
http://www.parelectronics.com
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Labels:
DeMaw--Doug,
Drake 2B,
EME,
moonbounce
Wednesday, December 4, 2013
Thermitron (Tube, Valve) Op-Amps
It is kind of appealing. I like it better than the 741. This one you can take apart and see how it works. Thanks Rogier!
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Labels:
radio history,
Tubes
Monday, December 2, 2013
On the suffering of Geeks. Indeed, we suffer...
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Labels:
Knack Stories
Sunday, December 1, 2013
11 MHz IF for new BITX 20/40 Dual Bander? Also: Cabinetry and Socketry
I am gathering parts and
ideas for a BITX dual bander (20 and 40 meters). I know Farhan used a 10 MHz
filter for his "Simple SSB Transceiver." But I was thinking of going a bit
higher, to 11 MHz. This would allow me to run the VFO from 3.175 to 3.355 for 20
meters, and 3.695 to 3.875 for 40 meters. I'm hoping that I can do this with one
single VFO (Farhan used two VFOs), perhaps with a reed relay switching in some
additional capacitance for the other band. I'll also follow Farhan's lead and
switch the Low-Pass and Band-Pass filters with DPDT relays.
I set up a simple
spread sheet and looked at the VFO harmonics to see if any fell within the
desired tuning ranges. That looks OK. I have not looked at mixing products
between VFO and BFO. What do you folks
think? Would the 11 MHz IF for these bands work? Or are there evil birdies
lurking in my future?
I've gone ahead and
bought another wood box for the new rig (I didn't even have to suffer through a
second visit to the crafts store -- they are available on Amazon). I also got a
roll of copper sheeting at Home Depot. This time I will prepare the box
first, lining the inside with copper and preparing all the "socketry" (George
Dobbs' word) before putting the PC board in.
Labels:
BITX20,
Dobbs-George,
Farhan,
SSB
Friday, November 29, 2013
First Pictures of the Far Side of the Moon (1959!)
On October 7, 1959, the Soviets sent an "automatic interplanetary station" to the moon. This, in itself, was an amazing achievement. Even more amazing is how they managed -- using 1950s technology -- to photograph the far side of the moon and get the images back to the earth.
The Soviet document on the Harvard site (below) says that the transmitter put out "a few watts" and used semiconductors. There appears, however, to have been at least one vacuum tube aboard (the cathode ray tube used to scan the chemically developed photo negatives). Frequency modulated analog video similar to FAX) was used to send the data.
http://articles.adsabs.harvard.edu//full/1962IAUS...14....7L/0000007.000.html
From Wikipedia:
Luna-3 was the first successful three-axis stabilized spacecraft. During most of the mission, the spacecraft was spin stabilized, but for photography of the Moon, the spacecraft oriented one axis toward the Sun and then a photocell was used to detect the Moon and orient the cameras towards it. Detection of the Moon signaled the camera cover to open and the photography sequence to start automatically. The images alternated between both cameras during the sequence. After photography was complete, the film was moved to an on-board processor where it was developed, fixed, and dried. Commands from the Earth were then given to move the film into a scanner where a spot produced by a cathode ray tube was projected through the film onto a photoelectric multiplier. The spot was scanned across the film and the photomultiplier converted the intensity of the light passing through the film into an electric signal which was transmitted to the Earth (via frequency-modulated analog video, similar to a facsimile). A frame could be scanned with a resolution of 1000 (horizontal) lines and the transmission could be done at a slow-scan television rate at large distances from the Earth and a faster rate at closer ranges.
The camera took 29 pictures over 40 minutes on 7 October 1959, from 03:30 UT to 04:10 UT at distances ranging from 63,500 km to 66,700 km above the surface, covering 70% of the lunar far side. Seventeen (some say twelve) of these frames were successfully transmitted back to the Earth, and six were published (frames numbered 26, 28, 29, 31, 32, and 35). They were mankind's first views of the far hemisphere of the Moon.
More info: http://www.svengrahn.pp.se/trackind/luna3/Luna3story.html#Film
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Labels:
astronomy,
Russia,
satellites,
space program
Monday, November 25, 2013
A British Bicycle (and Workshops)
Experiments in Speed from SpindleProductions on Vimeo.
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Thursday, November 21, 2013
BITX Build Update #20 -- Switchable Crystals, South Africa QSO
I got tired of popping the hood and manually changing my VXO crystals. First I tried to switch the rocks using a rotary switch on the front panel, but I think the leads were too long and the output was kind of squirrely. So I dug around in the junk box and found a 12 volt double pole double throw relay. I put the crystal sockets across the two poles and ran leads from the armature terminals to the crystal terminals. I use the rotary switch to activate the relay. I cover about 41 kHz of the 17 meter band with the two crystals.
17 meters has been in great shape. On November 16 I had a very nice contact with Syd, ZS1TMJ in Glenwilliam, South Africa. That's about 8000 miles on 5 watts SSB.
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Labels:
17 meters,
BITX20,
South Africa
Wednesday, November 20, 2013
Naval Gun Turret as EME Dish Mount (VIDEOS)
Hack-A-Day ran a story on EME pioneer Zoltan Bay. In the comments section someone posted this memorable video about a moonbounce station in Central Kansas. Wow. Putting using naval gun as an AZ-EL rotor for the dish is really thinking outside the box. Then deciding to put the whole thing atop another tower... Great stuff.
Here is another moonbounce video. VE2ZAZ was using a smaller antenna (!) and JT65. FB.
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Labels:
Canada,
EME,
moonbounce,
video
Sunday, November 17, 2013
M0XPD's Digital Analog BITX -- Best of Both Worlds
Paul, M0XPD, has built a very interesting version of the BITX rig. His is on 40 meters. It features plug in bandpass and IF filters (great idea!) and uses DDS technology for both the BFO and VFO stages. Good going Paul! More details here:
http://m0xpd.blogspot.co.uk/2013/11/rising-to-challenge.html
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Friday, November 15, 2013
Standard Computer Crystals for 17 Meter SSB VXO and IF Filter
Pete Juliano, N6QW, is an electronic genius. The ideas in his SPRAT article will be of great use to all those who share in Doug DeMaw's devotion to VXOs and reluctance to spend money. I'm really tempted to go back and re-do my BITX using Pete's 11.52 MHz computer crystal super-VXO and 4.9152 IF (I could then take my expensive 23.1 MHz crystals and put them back in my Doug DeMaw Barebones Superhet). I also like Pete's DPDT reed relay crystal switcher too. Three cheers for Pete Juliano, Doug DeMaw, and SPRAT! And thanks to WB9FLW for reminding us of Pete's articles.
Hi Bill,
Your BITX17 really has me fired up! I came across an interested Super VXO
by Pete N6QW for use on 17 Meters.
He uses standard computer xtals (4.9152 MHz for the IF) and (3 - 11.520
MHz freq doubled in the VXO)
This gets you on 18.120 to 18.150 using these two standard
xtals.
See Link Below:
http://www.jessystems.com/Images/23%20MHz%20VXO.jpg
Thanks for all your efforts they are much appreciated!!
Best Wishes,
Pete WB9FLWOur book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
BITX20,
DeMaw--Doug,
Juliano -- Pete,
SPRAT,
SSB
Thursday, November 14, 2013
Beautiful French Aerial Photography Project. UPstagram! (Video)
We've put cameras in kites and rockets, but I think this is much cooler.
More details (and pictures) here: http://hackerloop.com/upstagram/
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
balloon,
France,
photography,
video
Wednesday, November 13, 2013
BITX Build Update #19 Layout, VXO, Bal Mod, Filter, PA
The files of the BITX20 Yahoo group were very useful to me during my BITX build. So I have decided to make a contribution myself. I uploaded a few drawings today. Here is how I laid out the circuitry on my 8 inch by 11 inch copper clad board. I included the isolation (Manhattan) pads for one of the bidirectional amps.
Here is the VXO. I built is on a separate board, but I could have put it on the main board.
Here is the balanced modulator and crystal filter.
Here is the power amplifier circuitry. Amazingly easy to stabilize.
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Labels:
BITX20
BITX (and W2AEW) on Hack-A-Day
The guys over on Hack-A-Day ran a little follow-up article on the BITX-17. Check it out:
http://hackaday.com/2013/11/13/bitx-a-return-to-hackers-paradise/#comments
They also had an article about Tek-Wizard Alan Wolke earlier in the week:
http://hackaday.com/2013/11/11/diagnose-and-repair-a-yaesu-ft-7800-ham-radio/
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Labels:
BITX20,
web sites,
wolke -- Alan
New Book About Heathkit Gear
Jeff Tranter, VE3ICH, has a new book out -- it is about Heathkit Test Gear. (Hey, I had that VTVM on the cover!) This book looks like it deserves a place under the Christmas trees of SolderSmoke fans. The book is available from Lulu.com, and Santa (or Mrs. Claus) can use the discount coupon below (Coupon code: CORNUCOPIA.)
http://www.lulu.com/shop/jeff-tranter/classic-heathkit-electronic-test-equipment/paperback/product-21272772.html
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Tuesday, November 12, 2013
Save 20% on SolderSmoke and other Lulu books (through Nov 15)
http://www.lulu.com/spotlight/soldersmoke
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
book
Saturday, November 9, 2013
That wonderful first contact, when the new HB rig is still on the workbench...
In this video, YC0AFF in Indonesia seems to be having as much fun with his new BITX as I've been having with mine. I think there is something special about those early contacts, when the newly finished (or not quite finished!) rig is still on the workbench. Designed in India and built by radio amateurs all around the world, the BITX has become a global ham radio phenomenon, reminding us that we form an International Brotherhood of Electronic Wizards.
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An Amazing French Workshop (Video)
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Friday, November 8, 2013
Knack-to-the-Max! Early Moonbounce
The link below will take you to an amazing collection of QST articles describing the early days of EME or "moonbounce." Very interesting. I was really blown away when I found out that Ross Bateman, W4AO, (pictured above, on the left) did the very first amateur moonbounce work from the small suburban Washington town that I live in now -- Falls Church, Virginia!
I am trying to find OM Ross's old address or more info about him. If anyone has an old callbook, could you please look up Ross Bateman, W4AO, aka W4XNB? He worked at the National Bureau of Standards.
The moonbounce story is filled with interesting technology and characters and clubs. Sam Harris and his Rhododendron Swamp VHF Society sounds like our kind of group! Scroll through the OK2KKW web site and you will come across our esteemed Doug DeMaw and Bill Orr.
http://www.ok2kkw.com/eme1960/eme1960eng.htm
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Labels:
Clubs,
DeMaw--Doug,
EME,
moonbounce,
radio history
Wednesday, November 6, 2013
Zoltan Bay and his Chemical Moonbounce Detector
In March 1944, Bay recommended using the radar for scientific experimentation, including the detection of radar waves bounced off the Moon. The scientific interest in the experiment arose from the opportunity to test the theoretical notion that short wavelength radio waves could pass through the ionosphere without considerable absorption or reflection. Bay's calculations, however, showed that the equipment would be incapable of detecting the signals, since they would be significantly below the receiver's noise level.
The critical difference between the American and Hungarian apparatus was frequency stability, which DeWitt achieved through crystal control in both the transmitter and receiver. Without frequency stability, Bay had to find a means of accommodating the frequency drifts of the transmitter and receiver and the resulting inferior signal-to-noise ratio. He chose to boost the signal-to-noise ratio. His solution was both ingenious and far-reaching in its impact.
Bay devised a process he called cumulation, which is known today as integration. His integrating device consisted of ten coulometers, in which electric currents broke down a watery solution and released hydrogen gas. The amount of gas released was directly proportional to the quantity of electric current. The coulometers were connected to the output of the radar receiver through a rotating switch. The radar echoes were expected [11] to return from the Moon in less than three seconds, so the rotating switch made a sweep of the ten coulometers every three seconds. The release of hydrogen gas left a record of both the echo signal and the receiver noise. As the number of signal echoes and sweeps of the coulometers added up, the signal-to-noise ratio improved. By increasing the total number of signal echoes, Bay believed that any signal could be raised above noise level and made observable, regardless of its amplitude and the value of the signal-to-noise ratio.26 Because the signal echoes have a more-or-less fixed structure, and the noise varies from pulse to pulse, echoes add up faster than noise. From: http://history.nasa.gov/SP-4218/ch1.htm
During the war, Zoltán Bay protected Jewish colleagues from Nazi persecution. In 1998, the State of Israel honored him as Righteous Among the Nations for his actions and listed his name at Yad Vashem.
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Labels:
EME,
Hungary,
moonbounce
Monday, November 4, 2013
SolderSmoke Podcast #156 -- Special Echolink Interview
http://soldersmoke.com/soldersmoke156.mp3
Special hour-long interview with Peter Parker, VK3YE
-- Early experiences with radio
-- CW
-- DSB Gear
-- Simple gear, and gear that is TOO simple
-- VXOs, Super VXOs and Ceramic Resonators
-- Building receivers
-- Chips vs. Discrete
-- Making the leap to SSB
-- The Knob-less wonder and the BITX
-- No need for a sophisticated workshop
-- Advice for new phone QRPers
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Labels:
Australia,
BITX20,
DSB,
Parker--Peter,
SolderSmoke Podcast,
SSB
Sunday, November 3, 2013
BITX Build Update #18 -- BITX in a Box?
I've really been enjoying using my BITX17 without an enclosure. Having all the electronics exposed on the workbench really accentuated the homebrew nature of this rig. But obviously it was time to box this thing up. At a local craft store, I found a wooden box that is exactly the right size for my BITX copper clad board. I put the BITX in the box yesterday. I kind of miss the exposed electronics.
The far left control is AF gain. The need for a few inches of wire to the pot has introduced a bit of AC hum. I'll try to knock this down with better shielding on the lead to the pot.
But this gets brings us too a bigger question: the need for a cabinet that shields. Obviously the wood shields it only from dust. I know there are some benefits to putting this thing in a proper metal box. The AC hum would be less of a problem. Also -- listen to this -- in the morning, before 17 opens, I can hear -- faintly -- the WWV transmission on 5 MHz (recall that the IF in this rig is 5 MHz). And if I ever build an external linear amp for this rig (I might), I guess a proper metal box would help prevent the kind of oscillation that often drives me crazy on these kinds of projects.
So, what do you guys think? Stick with the wood, or put it in a metal box? Any thoughts on putting metal shielding material around the inside of the box (thick aluminum of tin foil)?
(The other black control knob is for a rotary switch that will allow me to select among two or three crystals for the VXO. )
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Labels:
BITX20
Saturday, November 2, 2013
40% Off SolderSmoke Book!!! Through 4 November
And on all Lulu books.
Just use the coupon code FALLSALE40 at checkout.
http://www.lulu.com/spotlight/soldersmoke
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Just use the coupon code FALLSALE40 at checkout.
http://www.lulu.com/spotlight/soldersmoke
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Arecibo Birthday
Thanks to Bob Crane for this birthday alert:
The
Arecibo Observatory opened on this date in 1963. At a diameter of
a thousand feet, it's the largest single-aperture telescope ever built. It's
also got the largest focusing dish in the world, which gathers electromagnetic
waves from space. Located near the city of Arecibo in Puerto Rico, it's close to
the equator, which enables it to "see" (via radio waves) all the planets in the
solar system; within six months of its opening, it enabled scientists to study
the rotation rate of Mercury and determine that it rotated every 59 days, rather
than 88 as was previously thought. It's also been used for military purposes
like locating Soviet radar installations by tracking their signals as they were
reflected off the moon. It's provided the first full imaging of an asteroid and
also led to the first discovery of planets outside our solar system.
In 1999, it began collecting data for the SETI
Institute; SETI stands for "search for extraterrestrial intelligence," and the
organization looks for deliberate radio or optical signals from other planets.
The Arecibo Observatory also sends data over broadband to the home and office
computers of 250,000 volunteers, who, through the Einstein@Home program, donate
their computers to be used for data analysis during periods when they would
otherwise be idle. A year ago, three such volunteers in Iowa and Germany
discovered a previously unknown pulsar, 17,000 light years from
Earth.
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Labels:
radio astronomy,
SETI,
telescopes
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