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Thursday, May 19, 2011

The W8SX Drake Interview


Bob, W8SX, (aka "our man at Dayton") conducted an interview with Bill Frost, Service Manager for R.L. Drake -- a fellow who knows a lot about the history of our beloved (and ever-more-valuable!) Drake 2Bs:

-- The Drake 2-B was designed and built in the early 60’s, but was not continued because R4 was its replacement. It was hoped that the 2-C would be a replacement for the 2-B, but the companion CW transmitter 2NT caused hams to associate the 2-C with a novice station and the sales number show that is was not as popular because 2-B with non-novice hams.

-- Why no crystal filters? Crystal filters not considered because of cost in terms of design & parts. In addition the LC filters allowed the designers to provide passband tuning both easily and cheaply in the 2-B.

-- How did it stack up against other receivers of the era? The 2-B was better than anything else for sale except Collins receivers, which cost a great deal more. There was also the R390, which was available on the surplus market, but it frequently was not is good shape and again cost a lot more.

-- Who designed it? The 2-B was designed by several engineers, but principally it was both Milton Sullivan & Bob Drake.

-- Why the copper chassis? Bill was not sure on this point other than to say that the Cu was meant to keep corrosion of aluminum chassis components to a minimum. Later they use cadmium as in the R4C/T4XC combination. In a couple of instances the chassis was plated with chromium and these radios are very rare and expensive collector items.

-- How important was the 2-BQ multiplier? While this is a highly sought after item today not very many were sold with the 2-B or even the 2-C. Today these are very valuable and command prices well above their original list price.

-- Was dial parallax a problem considered in the design? Not really as the crystal calibrator was supposed to be used along with the lines on the main dial slide to indicate the exact frequency. Band to band variation was very good for the time at around 3kHz. Not bad for a press DDS VFO.

-- Does he still have a 2-B? YES! And he would not part with it for any amount of money.

-- How many were made? He was not sure about this, but did say that the receivers are numbered consecutively, so that by knowing the first 2-B and the first 2-C it’s a simple subtraction to find the numbers of each manufactured.

-- Was it a big seller for Drake? Yes, but the R4 line which had a longer run and therefore sold more. The TR-3, and TR-4 line was a big seller for many years until the Japanese cut into their market share.

-- The TR-7A was Drake’s last ham gear and now they manufacture only home and commercial satellite receivers. These sell well to commercial cable, dish network, lodge net, channel modulators, D-A converters. They are now located in Franklin OH.

-- No ham gear is made by Drake these days as it is all commercial receivers for the satellite TV/radio market. The R8 was their last ham receiver and it still sells well on the used market.

-- For replacement tubes look to http://www.tubesandmore.com/. The transmitting tubes, 6JB6’s, are particularly hard to find. Look for a substitute sweep tube that can be used in that circuit.

-- John M Cherry, John Covelli, WB4HFN and Evin Rolek K9SQG@aol.com host the Drake Forum every Dayton Hamvention run by. A good resource for repair is John Kriner, WB4HFN

-- Drake's web sites: http://www.n9bor.us/drake.htm & http://home.online.no/~sindtorp/

To preserve the parts on a 2-B, especially the cosmetic parts, keep it out of sun & don’t smoke. These parts are particularly had to find these days.


Wednesday, May 18, 2011

How many Drake 2-Bs? The German Tank Problem

I have #11,976!
-------------------
Hi Bill,

I was just listening to your latest soldersmoke podcast and your
discussion about how many Drake 2Bs were made. Without knowing the
exact serial number for the last Drake 2B before the Drake 2C was
made, you can estimate what that number might have been by knowing a
few of the real serial numbers that are being used by people today.
This is a
mathematical problem related to the somewhat famous "German
Tank" problem. Check out:
http://en.wikipedia.org/wiki/German_tank_problem.

If you were to ask your listeners to report to you their Drake 2B
serial numbers you could estimate the largest serial number there ever
was from the formula on that wiki page. This could be a fun exercise
:) I've never had a Drake 2B so I can't contribute. But I could do the
estimate for you if you gave me the numbers.

Cheers and 73

Scott (K6AUS)

Alan's "Scopes 4 Dopes" (present company excluded, of course)

Hi Bill,

As a follow on to the Scope 4 Dopes class that I told you about (email below - and thanks for the shout-out in #133), I have put a few more videos on YouTube. One is on the use of the Delayed Timebase feature available on the more professional analog scopes - probably not of much interest to you. But, the other two are on taking a little bit of a tour of the RF signal path of the TenTec 1254 Dual Conversion Shortwave Receiver kit that I built over the Christmas vacation. I thought these might be of interest:

(I promise - these are not as long as the 2hr Scopes4Dopes tutorial video!!)

The tour through the 1254 with a look at some of the signals along the RF path (~12min):
and a short one looking at the modulated and demodulated 2nd IF on a live shortwave signal (~2min):

Enjoy.

73,
Alan W2AEW

Tuesday, May 17, 2011

EDN Article on April 1 and other Pranks

Bob, W8SX, alerted me to this gem. Geek thrills.

http://www.edn.com/blog/Anablog/40759-Pranking_bosses_friends_and_competitors_.php

Here is one of my favorite segments (it involved a 'scope and a soldering iron):


You should beware of prank escalation. Len Sherman, application engineer at Maxim recalls a prank exchange with Jim Williams when they were at MIT. As he loves to do, Williams had bought an old broken oscilloscope and worked on it all day, bringing it back to life and perfect operation. After Williams went home for the night, Sherman put a piece of toilet paper under Jim’s oscilloscope graticule. The paper was unnoticeable, but made the scope trace fuzzy. It looked like a focus problem. Jim went crazy the next day trying to fix this problem. He had the covers off and was measuring all the high voltage circuits. It took a few hours before he found the paper.

To retaliate, Williams took the hinge pins out of the lab door and tied a rope to the doorknob that he pulled back into the room, threw over a beam in the ceiling, and tied to 100 pounds of ballast. The next morning Sherman put the key in the lock and turned the knob. The entire door left it hinges and glided, upright, back into the lab about 10 feet. It then stopped and fell over. “It looked like something out of a Stephen King movie,” recalls Sherman.

Sherman then rigged up a water nozzle to a photo-switch triggered by the lab lights. He rigged a soldering iron with coil of solder around it used as a fuse, to time out the prank. Sherman didn’t want to flood the lab, just run the water nozzle for a minute or so. Williams got wet.

Sunday, May 15, 2011

SolderSmoke Podcast #134


http://soldersmoke.com/soldersmoke134.mp3

May 15, 2011
New "Ikea" microphone
NOVA QRP Club

WSPR T/Rouble resolved
Finishing up Rome WSPR rig
Easy-Peasy on Asus eee-PC

Space Station Packet Beacon
Boatanchor News: DX-100, HT-37, "CQR" anchors, 75 meter antenna Drake 2-B history interview by W8SX
Lew McCoy and Ernest Hemingway
Ade Weiss, QRPoetry and Ade's new book
Regen theory

MAILBAG (with a focus on New Zealand)

Friday, May 13, 2011

Landing on Titan to the Sounds of Saturn



These are real images from the Huygens probe. And the sound is apparently from the radio signals generated by Saturn. I agree -- it sounds nicer than Jupiter!

Wednesday, May 11, 2011

Euro Zone: SolderSmoke Kindle-book Now Available

SolderSmoke -- Global Adventures in Wireless Electronics is now available on the Amazon.de (German) web site. Payment in Euros.
https://www.amazon.de/dp/B004V9FIVW

Monday, May 9, 2011

WONDERMARK! (Comics with the Knack)

As part of our occasional series on Knack-related comic strips, today we present Wondermark. This link will take you to the first page: http://wondermark.com/tink1/ From there, look for the little "NEXT" hand on the right of the comic. There are eight. All of them are gems. Also, be sure to check out the author's bio:
http://wondermark.com/about/


Friday, May 6, 2011

WSPR -- THE MOVIE!



VK2TPM made some nice videos of the Weak Signal Propagation Reporting System (WSPR) maps over time. Its kind of fun to watch the propagation shift from trans-Atlantic to trans-Pacific.

More: http://www.youtube.com/user/vk2tpm#p/u/4/U1sBGZzNv8s

Thursday, May 5, 2011

T/R Success with WSPR

Thanks to everyone who sent in advice on my WSPR t/r troubles. I now have it all sorted out. In the image above you can see the cable from the serial port that carries the RTS T/R signal from the computer. It goes to a switching transistor that controls a relay that in turn switches the three relays that actually do T/R for the rig. One question: On the Linux computer the RTS signal seems to switch between +5 and -5 volts, but on the Windows machine it was +10 and -10. Why?
I'm really pleased to have the computer interface working. It is kind of neat to bring together the complex technology of the computer and the simple technology of a DSB/Direct Conversion rig.

Wednesday, May 4, 2011

Five Planets Visible in the Morning

The good folks over at spaceweather.com have once again alerted us to an important astronomical event: During May, early risers will be treated to a conjunction of Mars, Jupiter, Venus, and Mercury. (The fifth visible planet would be the one you are standing on!) The Moon is thrown in as a bonus. The photo above was taken by Liz Gleeson on Magnetic Island (Australia) -- what a great location!

Monday, May 2, 2011

More T/Rouble

I get the RTS signal when using a Windows PC, but when I try to switch over to a Linux computer, I don't get the T/R signal from pin 7. Is there some code or setting in Linux that I need to change to make this happen?

Saturday, April 30, 2011

Working on T/R circuit for HB WSPR rig --need help!

I'm finally working on the PTT T/R circuit for my homebrew DSB /Direct conversion 30 meter transceiver. I hope to use the simple one transistor circuit from W3PM's FB HB WSPR rig.

But I need info on the PTT signal that will come from the computer serial port. Which pins on the 9 pin serial port connector? What kind of signal comes out? Is it 5 volts on transmit? What settings should I use in WSPR? RTS? Any other setting changes needed?

I hope to be transmitting AND receiving soon.

Friday, April 29, 2011

AMSAT OSCAR 7 -- No Batteries, Running Directly From Solar Panels

From the AMSAT site:

AMSAT-OSCAR 7 was launched November 15, 1974 by a Delta 2310 launcher from Vandenberg Air Force Base, Lompoc, California. AO-7 was launched piggyback with ITOS-G (NOAA 4) and the Spanish INTASAT. Built by a multi-national (German, Canadian, United States, and Australian) team of radio amateurs under the direction of AMSAT-NA. It carried Mode A (145.850-950 MHz uplink and 29.400-500 MHz downlink) and Mode B (432.180-120 MHz uplink and 145.920-980 MHz downlink (inverted)) linear transponders and 29.500 and 145.700 MHz beacons. The 2304.1 MHz was never turned on because of international treaty constraints.

In mid 1981 AO-7 ceased operation due to battery failures. It was thought at that time that the batteries had shorted. However on June 21, 2002, at least one of the shorted batteries went open-circuit, allowing the satellite to waken whenever it is in sunlight, and randomly begin operation in one of 4 modes.

According to the log at planetemily.com/ao7/ao7log.php, this old warrior is still supporting transponder action in mode A and mode B as recently as 9/10/09, and on a regular basis, whenever it is in sunlight.

When the satellite is in sunlight for extended periods of time, the 24-hour timer still switches the bird between modes A and B. Listen for the corresponding beacon to determine which mode the satellite is currently operating in, or refer to the above mentioned web page to see what mode has recently supported QSO\'s as the best estimate of what is the current mode of operation.

Please remember, there are no (functional) batteries, so the satellite\'s power input is limited to whatever output can be generated by the ancient solar panels. Use the least uplink power possible to minimize your downlink power usage, and maximize the number of simultaneous QSO\'s supported in the passband. There are other operating tips at:http://www.planetemily.com/ao7/usage.php
Linear transponder birds are a scarce commodity these days, so please use AO-7 responsibly, but please DO enjoy her!

Wednesday, April 27, 2011

50th Birthday of the Silicon Integrated Circuit



Robert Noyce got his IC patent on April 25, 1961.

Of course, wave soldering would be something to come out of California.

Tuesday, April 26, 2011

Free Kindle Reader for your PC

This link will take you to the download site. The software will allow you to use your PC as a Kindle reader.
http://www.amazon.com/gp/feature.html/ref=kcp_pc_mkt_lnd?docId=1000426311

Then be sure to get a copy of SolderSmoke -- The Book
http://www.amazon.com/dp/B004V9FIVW

Sunday, April 24, 2011

SolderSMOKE APRS symbol

I've been setting up my satellite APRS station. This weekend I finally got the UI-view software running. I had to pick an icon -- this would be the symbol that would show up on the mapping software. In the Azores I had a nice little island with a palm tree. Here in Virginia, well, as I scrolled through the options, suddenly I saw something that seemed appropriate. The coordinates are a bit off, but that, my friends, is a smoke stack emitting 60/40 fumes.

How to Join G-QRP (and get SPRAT) in the USA


From the G-QRP web site:

Formed in 1974, the GQRP Club is a non profit organisation run entirely by volunteers to promote Low Power Radio. Whether you have a ham licence or not - everyone is welcome. Our quarterly magazine SPRAT provides a fascinating read containing articles of varying complexity, from simple test equipment, to fully functioning radio transmitters and receivers. Membership fees are about as low as you will find anywhere and our club sales service to members is second to none.

Indeed. Joining G-QRP and getting SPRAT is something all QRPers and homebrewers should do!

Some SolderSmoke listeners have asked me how they can join G-QRP from the U.S. Bill Kelsey is the club's man in America:

Bill Kelsey - N8ET 3521 Spring Lake Dr., Findlay, OH 45840 U.S.A.

$18 paid in USA.


Bill's e-mail and more info here:
http://www.gqrp.com/memb_usa.htm

OR... You can pay directly via PAYPAL:

http://www.gqrp.com/paypaldx.htm