First Amateur Transatlantic SSB Contact W2TGO--DL4PA September 9, 1949

Mars: Book Review, Martian Propagation, Martian Moons as VHF Repeater Sites

In SolderSmoke #224 I mentioned the Mars Trilogy by Kim Stanley Robinson.   I found a book review in The New Yorker (see below).   In Red Mars they mention that there is no ionospheric propagation on Mars.  W1PJE and K1RID point out that this is incorrect -- there is ionospheric propagation on Mars.  K1RID provides a link to a really detailed NASA study of this question (it includes discussion of the effect on propagation of Martian dust storms -- good to know!). Finally, 2E0CHK suggests placing VHF repeaters on the two moons of Mars.  I found a good article about the overhead passes of these moons.   See below for all.  

AND REMEMBER: THE ELSER-MATHES CUP REMAINS UNCLAIMED! 


Here's a review from The New Yorker: 

https://www.newyorker.com/books/page-turner/our-greatest-political-novelist

----------------------------------

Hello Pete and Bill,

Listened to your latest SolderSmoke podcast. Enjoyable as always. But you should correct the record: Mars does have an ionosphere!

https://www.google.com/amp/s/www.wired.com/2017/04/mars-ionosphere-cold-lifeless-filled-heavy-metals/amp

The peak daytime electron density ("M2 layer") is low in altitude - perhaps 130+ km, about our E region - and density is like our E region too (5-10x lower than our F region). So for the Mark Watneys carrying their Homebrew rig and inverted V, probably only a few hundred km to the first skip zone. More NVIS flavor than anything else.

Fun to think about. You should go and test it out!

73

Phil W1PJE

-------------------------------------------------

BTW, this made the rounds in our club last year:

https://descanso.jpl.nasa.gov/propagation/mars/MarsPub020318.pdf

dit dit

73 de Ed, K1RID
Newburyport Electronics & Radio Society
www.K1YRD.org

------------------------------------------

2E0CHKAugust 1, 2020 at 4:04 PM

Hey Bill,
No skip on Mars ?
No ionosphere ?
Every cloud has a silver lining, even if Mars doesn't have any clouds ;)
Mars has two moons.
Could be paradise for Moon Bounce aficionados. No ionosphere or F layer to get in the way. VHF can get around corners after all.

-----------------------------------

Here is an article describing the overhead passes of the two Martian moons: 

https://www.space.com/28403-astronauts-mars-skywatching-phobos-deimos.html#:~:text=So%20an%20observer%20on%20the,and%20set%20in%20the%20west.

How to Sweep, Plot, and Measure Filter Output in LTSpice

The other day Pete N6QW posted a very nice graph of a bandpass filter's passband.  He was using LTSpice.  I realized I had a serious gap in my LTSpice knowledge -- I wasn't sure how to do this.

The charming video from India explains how.  Really useful.

OSCAR 100 Geosynchronous Satellite Video

I guess the title for this post could also be "How the Other Half Lives."  I'm sure at least a few of you will be thinking about building an OSCAR 100 station after watching this video.  But if you are in North or South America (with the exception of the Eastern tip of Brazil), forget about it.  OSCAR 100 is geostationary over the other side of the planet.  And amateurs have no equivalent on this side of the world.  But we can listen in using the Web SDRs. 

A couple of interesting bits from this recording.  You can hear G7BTP's coming back from the satellite with a bit of a delay -- he is obviously monitoring the downlink when he is transmitting.  DL8FBH says that he doesn't have a receive system of his own -- he is using a WEB SDR station (as I was) for the receiver. 

  

Homebrew Resistor Kit -- Drew's Mouser BOM

I put the resistors in parts envelopes and cardboard boxes

Hi Bill,

You mentioned wanting to get a resistor kit.  If you'd like, I can

help you do what I did.

First, I looked at:  https://en.wikipedia.org/wiki/E-series_of_preferred_numbers

Then I noodled about it a bit.  And looked at mouser.

A tiny bit of code put together a copy and paste list of part numbers

that I pasted onto mouser's BOM order form.  And bob's your uncle.

In my case, a particular manufacturer's 1/4 W metal film 100 ppm as

they were 1.9c @ 100 pieces.  I created a copy and paste BOM for E6

over 4 decades plus E3 for a 5th and 1M and 49.9 ohms. Less than $2

per value for 29 values.  Not a bad price for the size of the resistor

kit.  I also figured if the value gap was too large, I could fill it

in with the other half of the E12 series.  (E6 series is every other

E12 series value.)

This could be tweaked.  Perhaps fewer resistors in each value.  Or add

some more special values or whatever.

Mouser was kind enough to cut tape and put each value in a flat

plastic baggy with a label as to what was inside.  Sorted in a file

box, it's a snap to grab a resistor.

Perhaps this is something I should post online to share?  Maybe

someone else already has?

On my todo list is to construct my self a homebrew BOM of capacitors.

If you're interested, I could update this and let you know what Mouser

can do for you.  It may not be your preference, but it is an

interesting option.

Best regards,

Drew

n7da

--------------------------------

Drew:   Your message caused me to think about what I really need in a resistor kit.  I have been using some other resistor kits, but I end up using ALL of certain values and NONE of others.  Your message made me realize that there is valuable data in those old kit packages.  

I took a look a them this morning.   It seems I use the following values:  4.7, 10, 47, 100, 220, 330, 470, 1k,  2,2k, 3,3k, 4,7k, and 10k.  That's about it.  So maybe I just need to go to mouser and order, 50 of each.  I'm thinking 1/4 or maybe 1/2 watt? 

The packaging you describe sounds great.  How can I get Mouser to do that for me?  

I don't think I need the more sophisticated approach you used, but I'm sure we have listeners who could benefit from it. 

Any further suggestions?  

Thanks again,  

73  Bill 

-----------------------------

Hi Bill,

Sounds very good.  It turned out to be simple for me to order a
ridiculously well stocked resistor kit, but doing something custom is
actually a great idea.  If you want both 1/4 and 1/2, get both.  (I
figured I could always make a 1/2 W resistor out of 2 1/4 watt
resistors.)

The packaging is just what they do.  No extra charge other than their
regular shipping and handling.

So, I did this in late 2018.  When ordered, two values were
backordered, but they shipped them out a month or 6 weeks later or
something.  Checking now, 660-MF1/4DC1000F (a 1% 100 ohm metal film
1/4 watt), I see it is out of stock with an ETA of June 1st for 10K
they are ordering.  The other P/N that was backordered was
660-MF1/4DC1503F.  Who knew 100 and 150K ohms were extra popular?
150K is in stock right now BTW.  Maybe it's random what they run out
of?

Best thing is you copy and paste your list of P/Ns and quantity for
each and bam Mouser will tell you pricing and if anything is
backordered, etc.  If you don't like what you see, change your list
and try again.

I actually thought about what I wanted, then looked at Mouser to see
what they had and what the pricing was on it.

So, from this particular resistor family, I see the pricing is what it
was a couple of years ago.

if you order 50 pieces of that 150 or 100 ohm resistor, that is:
50*$0.055 = $2.75 for 50 resistors.

If you order 100 pieces of that 150 or 100 ohm resistor, that is:
100*$0.019 = $1.90

IT"S CHEAPER TO ORDER 100!  Well, at least for this resistor family
and for Mouser's price breaks.  You have to look at the price breaks
versus volume.  And of course, understand the minimum you need and the
maximum you can store in your lab.  :-)  Don't be ordering 10,000.
:-)

So, price breaks for these they show:

Qty.    Unit Price
1    $0.23
10    $0.055
100    $0.019
1,000    $0.014
2,000    $0.009
10,000    $0.008
25,000    $0.007

You can see that there's a good break at 10, 100, and 2,000.  The
quantity with a good break really depends, so you would have to look
at different vendor product families to see.  I don't think I looked
very long.  I probably knew I wanted 1/4 W (may have considered 1/8 or
1/2, don't remember).  I also think I knew I wanted metal film.  When
I saw the pricing on these at 100 pc and with 1% tolerance (so I could
double out to E12 series and have it make sense if it turned out to be
useful for me), I stopped shopping.

Here's the full BOM I ordered.  The top part is some extra parts I
wanted and those couple of special resistor values.  The lower part
was generated by just a few lines of python:

-----
G6K-2F-Y-DC12|8
1N4007FFG|100
1N4448|100
2N3904TAR|100
2N3906TAR|100
2643000101|100
2643002402|25
2673002402|25
2661000101|25
1C10X7R104K100B|50
1C10X7R103K100B|50
ECA-1HM101|25
ECA-1HM100|25
TIP29CG|5
TIP30CG|5
1N5355BG|10
PR01000104700JR500|10
PR01000102200JR500|6
MF1/4DC1800F|20
MF1/4DC2400F|20
MF1/4DC36R5F|10
FC2053-440-A|100
MF1/4DC16R5F|20

MF1/4DC10R0F|100
MF1/4DC15R0F|100
MF1/4DC22R0F|100
MF1/4DC33R0F|100
MF1/4DC47R0F|100
MF1/4DC68R0F|100
MF1/4DC1000F|100
MF1/4DC1500F|100
MF1/4DC2200F|100
MF1/4DC3300F|100
MF1/4DC4700F|100
MF1/4DC6800F|100
MF1/4DC1001F|100
MF1/4DC1501F|100
MF1/4DC2201F|100
MF1/4DC3301F|100
MF1/4DC4701F|100
MF1/4DC6801F|100
MF1/4DC1002F|100
MF1/4DC1502F|100
MF1/4DC2202F|100
MF1/4DC3302F|100
MF1/4DC4702F|100
MF1/4DC6802F|100
MF1/4DC1003F|100
MF1/4DC1503F|100
MF1/4DC2203F|100
MF1/4DC3303F|100
MF1/4DC4703F|100
MF1/4DC6803F|100
MF1/4DC49R9F|100
MF1/4DC1004F|100
-----

So, your BOM (4.7, 10, 47, 100, 220, 330, 470, 1k,  2,2k, 3,3k, 4,7k,
and 10k) would be the following.  Added the 4.7 by hand and deleted
the other values by hand.  Qty 100 each.
-----
MF1/4DC4R700F|100
MF1/4DC10R0F|100
MF1/4DC47R0F|100
MF1/4DC1000F|100
MF1/4DC2200F|100
MF1/4DC3300F|100
MF1/4DC4700F|100
MF1/4DC1001F|100
MF1/4DC2201F|100
MF1/4DC3301F|100
MF1/4DC4701F|100
MF1/4DC1002F|100
-----

Mouser.com.  Services & Tools button.  BOM Tool button.  Login (they
want account for the tools.  I can't complain.)  Upload spreadsheet or
copy and paste.  In this case, copy and paste.  In fact, copy right
out of this draft email and into their tool.  Next.  Then they ask me
for a name for the BOM and if I only want RoHS.  (RoHS is up to you.
I picked only RoHS, because I know all these parts are RoHS and it
won't warn me about lead poisoning or anything.)  Process BOM.
Blammo.

I had the 4.7 wrong, but they figure it out.  Ouch.  Pricey.  Maybe
you don't need so many, but $4.6 for 100.  Parallel a couple of 10
ohm, you'll have less parasitic L in your emitter circuit.  Change the
BOM before you click the add all to cart.  No problem.  Or maybe 4.7
is worth the extra money to a high roller such as yourself.  :-)

2 parts are at 0 inventory.  The 100 we knew about.  470 as well with
6K arriving 15June.  Yes, those ETAs are perhaps questionable.  Dunno.
They will ship you what they have and ship the rest later AT NO EXTRA
CHARGE.  :-)

A third part is at 123 pc inventory.  Act now before they are all out!
:-)  220 ohms.  6K due end of June.

The above would be $25.50 plus less than $10 for their cheapest
shipping option.  Not a bad price for a well stocked CUSTOM kit and
it's really easy to do.  And these are good parts with specifications
and tempcos etc. all in the data sheet.  Sure, you don't need it 99%
of the time, but if you wanted it, because you were doing something
fussy, you have it.

You could cut that price down quite a bit if you went carbon or wider
tolerance.  (Who needs 1%?  This is electrical engineering, not
mechanical engineering!)  Or maybe another manufacturer.  It's easy to
browse on Mouser and figure out those other options quickly and what
it may do to help you out.  Of course, when you get to a price of
$0.00, you still have the flat rate cheapest Mouser shipping as the
floor on what price you can achieve.

Mouser will also give you a print and email with price, part number,
description of everything in your custom kit.  And each pouch is
labelled.  Crazy!  :-)

Another crazy thing is with these BOMs is that you can easily share
them with others.

Best regards,

Drew
n7da

SolderSmoke Podcast #224: Mars. Spurs. Bikes. SDR. NanoVNA. Antuino. MAILBAG

SolderSmoke Podcast #224 is available:

http://soldersmoke.com/soldersmoke224.mp3

1 August 2020

--The launch of Perseverance Mars probe with Ingenuity helicopter.

--China’s Tian Wen 1 on its way – radio amateur Daniel Estevez EA4GPZ is listening to it! 

--Sci Fi Books:  Mars Trilogy by Kim Stanley Robinson.  No skip on Mars :-(

--We have some sunspots!  SFI now 72 and the Sunspot number is 23. 

Bill's bench: 

--Conquering Ceramic Spurs in Q-31   Roofing filter -- sort of 

--NE602 for a Q-75 converter – Gilbert Cell. 

--Measuring low power levels out of NE602.  Antuino better than 'scope . 

--NanoVNA   Really cool stuff.  SDR in there. 

--Building a 455 kc LC filter from QF-1 rubble. Using LTSPICE, Elsie... 

--Reviving my bicycle AM radio – The “All Japanese 6”

--Understanding L Network impedance matching. 

--Bill’s new resistor kit from Mouser. Thanks to Drew N7DA. 

SHAMELESS COMMERCE:  PATREON, AMAZON SEARCH.  THANKS

Pete's Bench: 

--Lockdown Special 

--BPF work on SDR Rig

--I U W I H 

Mailbag:

VK3HN Summit Prowler 7

VK2EMU “The Stranger”

SM0P  HB uBITX in Dubai

AE7KI  Worked him in VK from London

ON6UU  EA3GCY’s 4020 rig

KA4KXX A Simpler Mighty Mite

W9KKQ M19 DMR

KD4PBJ Radio Schenectady

W3BBO 12AU7 Regen

KE5HPY Another 12AU7 regen

N5VZH Ne602 Converter

KY3R Wall Art

G4WIF  Spectrum Analyzer in your pocket

W2AEW  Talks to UK Club

KK0S Sent 455 Kc IF cans

KL0S Making 9Mhz filters

VU2ESE  Diving into simple SDR schemes

Dean KK4DAS  Amateur Radio Astronomy

D-Lab Re-Caps a Drake 2-B (Very Economically)

A bit ugly, but it gets you there!   I like it. 

Thanks to John KE5ETX for alerting us to this video. 

A 75 Meter AM Quarantine Converter for the Q-31 Receiver (video)

A while back Fred KC5RT sent me a nice collection of parts, including some 6 MHz crystals.  I had been thinking of making a converter to put ahead of my Q-31 receiver.  When Fred's 6 MHz rocks arrived, I knew that The Radio Gods Had Spoken (TRGHS).  

I found some NE602 chips in the junk box.   I used an Altoid-sized box for the case.  The toroids are from W8DIZ.  I use trimmer caps from KC5RT to resonate the input and output circuits.  

Hooray!  Now I can listen to 75 Meter AM on the Q-31.  I may have to build a transmitter to go with this contraption.  

Thanks again Fred. 

Paul Taylor's Quarantine "Summit Prowler 7" and some Radio Archaeology

Paul Taylor VK3HN has really outdone himself in this video (above) and blog post. He describes coming across a somewhat mysterious homebrew SSB exciter with some cryptic markings on it. Paul eventually figures them out.  We still don't know who the builder VK3WAC was -- can anyone find him in their logbooks? 

As Paul goes through the description of the transceiver he built around the mystery exciter, he mentions a number of hombew heroes including Farhan VU2ESE, Peter DK7IH, Eamon EI9GQ (I have to get his book!), and Don W6JL.  Also,  our beloved SSDRA book plays a prominent role in the story. 

Paul's video is really beautiful -- at one point the camera pans the landscape and we see kangaroos in the field.  It is also refreshing  -- as we suffer in the heat of the northern hemisphere summer -- to see Paul and his friends out on the summits in their winter coats and hats.  

It looks to me as if Paul built this rig during the current emergency, so I will list it as a Quarantine rig.  Every dark cloud has a silver lining, and Paul's rig has added a bit of silver to the dark COVID cloud.  Thanks Paul. 

https://vk3hn.wordpress.com/2020/07/26/something-old-something-new-a-four-band-5w-50w-ssb-cw-transceiver-summit-prowler-7/

Alan Wolke W2AEW on IMD, NanoVNA and more (presentation to UK club)

This video is another reminder of how lucky we are to have Alan Wolke W2AEW as a fellow radio amateur, and as a teacher and mentor. 

In this video, Alan is talking to the Denby Dale Amateur Radio Society in Yorkshire, UK. 

The first part of his talk is about IMD products, the importance of 3rd order products, and the benefits of attenuation. 

The second part of the talk (after a few questions) is a look at the NanoVNA, which Alan cites as the "Toy or Tool of the Year."   

I learned a lot from both portions of the presentation.  I now find myself wanting an H4 model of the NanoVNA (bigger screen).  Or maybe even an F model.   Thanks to Alan, I now know what S21 and S11 means. 

Thank you Alan, and thanks to the Denby Dale ARS.  

73  Bill 
  

ANOTHER 12AU7 REGEN! W3BBO's Quarantine Receiver

Hi Bill,

I was really impressed with Chuck KE5HPY’s 12AU7 Quarantine Regen!  A very nice build and my hat is off to him!  It caught my eye, as I also built a 12AU7 regen during this period, my first “Hollow-State” unit in sometime. 

It would be interesting to find out what other construction projects fellow hams have involved themselves with during this trying time.

Keep melting solder!

73 de Bob W3BBO

  

Radio Schenectady

A while back I posted a picture (see below) of the shortwave dial of an old receiver used by my wife's grandfather.  I noted the odd  presence of 'Schenectady"  among the exotic foreign locations on the dial.  Pete immediately connected the dots by noting that Schenectady was the home of General Electric.  This week Chris Waldrup KD4PBJ sent us a great web site describing the shortwave stations in Schenectady.  Check out the tube that runs 100 kw AM (Big Bertha).  

https://www.radioworld.com/news-and-business/schenectady-shortwave-transmitters-1941

Chris also sent information about BIG AM broadcast band stations: 

In addition to Schenectady being home to  GE it is the city of license to clear channel AM 50 kW WGY 810.  WGY was started by GE so if the radio was GE it was probably a way to promote their station at the time. I heard mention of Rochester too and that would be for 1180 WHAM another 50 kW clear.  Both WGY and WHAM are still there going strong banging out their 50 kW.

And Pete reminded us of KDKA, describing its long-lasting impact on one of his ears:  

Let us not forget KDKA in Pittsburgh at 1020 which I think is no longer clear channel. I used to listen to KDKA on my crystal set when I went to bed at night. My bed had an exposed bed-spring which was my antenna. To this day there is a slight kink in one of my ears where my Brush headphones rested –I am a side sleeper.