Author: Peter Marks

Another LM373 Rig – Pete Is Not Alone!

The Radio Laboratory at Bandung, Java — SSB in 1927


 Anton PA0AST alerted me to this important piece of radio history:

The first phone radio between Indonesia , the city of Bandung ( Dayeuh Kolot, Jalan Radio 1 ), and Holland , Radio Kootwijk were made in SSB already in 1927… Before that time they had only a CW 1 Mega Watt spark transmitter in Malabar.
One of the receivers still exists in a museum in Amsterdam (cdvandt ). It is 3 meters in length and 2 meter in height…. All made with plug-able units with 1 tube inside .

The transmitter was 10 kW. Ua was 6kV was made by dynamotors. Transmitting Tubes locally made by craftsman in a workshop. Both buildings as well in Bandung and in Kootwijk still exists .

 Anton

 The old images come from:
http://www.cdvandt.org/bandung-lab-kwk.htm

At the other end was Radio Kootwijk in Holland.

Before you jump to the English version of the page, be sure to check out the Drone video of the site, and the audio file of the Morse transmissions:

http://radiokootwijk.nu/ Thanks to PA0JWU for the wonderful site.

Quite an impressive shack! My favorite part is the note indicating that local residents cleaned out the cooling pool and used it for swimming each summer.

AC9JQ’s Mini Digi VFO/BFO Al Fresco with OLED (and noise test)

From Dean AC9JQ:

Just completed the VFO/BFO/Arduino/OLED module for my radio. I also have the LPF, BPF and crystal filters completed and tested. Next will be the audio amplifier and NE602 modules. I will probably build one of the NE602 modules and test things out as a DC receiver. My ultimate plan is to have the rig no more that 1″x3.5″x3″. I still have a lot of “stuff” to stuff into that size of box. I’ll keep you posted.


 I have been able to contain the entire Arduino/Si5351/OLED into a small cube in the front. The rest of the radio has to fit on two levels in the rest of the area behind the Arduino/Si5351/OLED. I think I will build the audio section and on NE602 mixer and run it as a direct conversion first to vet out any noise or other problems. Bill, that small coax that you pointed out will really help on this build. I used a small piece as a power feed-thru and will use it to feed out the VFO/BFO signals, thanks again for that pointer.

I decided to test for noise on the TIA transceiver test bed. See the video of the results. Not too much noise. I’m only using my indoor magnetic loop for an antenna. Video is kind of sloppy, but taking off the antenna and turning up the volume shows how little noise is left in the system. Now time to stuff the rest of the radio into the tight quarters.


I purchased OLED from ebay…….

They are nice and compact, although as time goes on, I’m sure they will be harder to read. I’m hoping to have an alfresco version in a week or two. I used much of Pete’s code from the shirt pocket transceiver upgrade, modified the code to address the smaller display and add USB/LSB capabilities.

73’s Dean AC9JQ

AC9JQ’s Mini Digi VFO/BFO Al Fresco with OLED (and noise test)

From Dean AC9JQ:

Just completed the VFO/BFO/Arduino/OLED module for my radio. I also have the LPF, BPF and crystal filters completed and tested. Next will be the audio amplifier and NE602 modules. I will probably build one of the NE602 modules and test things out as a DC receiver. My ultimate plan is to have the rig no more that 1″x3.5″x3″. I still have a lot of “stuff” to stuff into that size of box. I’ll keep you posted.


 I have been able to contain the entire Arduino/Si5351/OLED into a small cube in the front. The rest of the radio has to fit on two levels in the rest of the area behind the Arduino/Si5351/OLED. I think I will build the audio section and on NE602 mixer and run it as a direct conversion first to vet out any noise or other problems. Bill, that small coax that you pointed out will really help on this build. I used a small piece as a power feed-thru and will use it to feed out the VFO/BFO signals, thanks again for that pointer.

I decided to test for noise on the TIA transceiver test bed. See the video of the results. Not too much noise. I’m only using my indoor magnetic loop for an antenna. Video is kind of sloppy, but taking off the antenna and turning up the volume shows how little noise is left in the system. Now time to stuff the rest of the radio into the tight quarters.


I purchased OLED from ebay…….

They are nice and compact, although as time goes on, I’m sure they will be harder to read. I’m hoping to have an alfresco version in a week or two. I used much of Pete’s code from the shirt pocket transceiver upgrade, modified the code to address the smaller display and add USB/LSB capabilities.

73’s Dean AC9JQ

G7WKE’s Crystal Tester

Wow, this is an example of dedication to the cause. I think many of us wimped out when confronted with the complex circuitry of the test device prescribed by DeMaw, but Rob G7WKE actually built the thing, and did a great job on it. I’m tempted to suggest that Rob might want to set up a small business leasing this rig out to less dedicated filter builders. Or perhaps he could have batches of crystals sent to him for DeMaw-ian analysis.

Hi Bill,
After listening to you and Pete discussing crystal filter design during SolderSmoke 197, I thought you might be interested in my latest project.

This is the Crystal Tester from January 1990 QST that is reprinted in W1FB’s Design Notebook, which I believe is the circuit you and Pete were referring to.

It all appears to function as it should, so the next step is to sit down quietly with a pile of crystals and hopefully start along the road to a working filter!

73s
Rob G7WKE.

The Workshop at AA8V

Field Day was a big success for me this year. I was in category “1E” which meant that I was home in the air conditioning, but doing my bit for emergency service by using a gel cell as my power source. A SOLAR CHARGED gel cell. So don’t anyone call me a slacker, OK?

I was on my HW-8 and made a total of two contacts. The second was with AH6AX. I wasn’t fooled — I knew they weren’t in Hawaii. But the op gave me his home call: WB8YYY. Curt is a SolderSmoke listener. In a follow-up e-mail he alerted me to the web site of AA8V. Great stuff. Thanks Curt.

Here is the AA8V workshop:

http://faculty.frostburg.edu/phys/latta/ee/workshop/workshop.html#electronics1

AA8V was on the QSO Today podcast not long ago.

Mod to Correct DESIGN ERROR in Heath HW-8

130k resistor inside heat shrink, across R-24
SPRAT 161 (Winter 2014/15) had a very intriguing article about the Heath HW-8 by Dave M0CEM. Dave wrote about a possible design error in the active filter of the receiver. The center frequency and gain shift significantly when you switch from “Wide” to “Narrow.” I was very interested because for many years I have noticed this problem in my own HW-8. I just left it in “Wide” and never used the more narrow filter.
Dave did some excellent circuit detective work and determined that the problem was R24. He prescribed a change: instead of 82k it should be 49.8k. The placement of a 130k resistor across the 81k R24 would have the same effect.
Yesterday morning I installed Dave’s mod. I did as he suggested and put a 130k resistor across R24. Brilliant! What a difference! In the past, I noticed a significant degradation in signal strength when I put the filter in the “Narrow” position. This doesn’t happen now — the response obviously does narrow, but the center freq stays the same.
It is really amazing to me that the Heath engineers made this error, and that it went uncorrected for so many years. There have been many, many modification articles for the HW-8 over the years, but I haven’t seen any that really address this problem.

If anyone has more info on how this design error happened and why it went uncorrected for so long, please let me know.

Thanks to Dave and SPRAT for getting us back on the straight and narrow.

Straight Key QRP Homebrew Adventures — TRGHS

Last Saturday I put the Tuna Tin Two Top together with my Herring Aid Five 38 (year) Special and the Indian key that Farhan gave me. I discovered that some of my 40 meter CW FT243 crystals had disappeared into the entropy of the shack. But I was able to find one for 7050 kHz. That was a bit of good luck because it turns out that 7050 is the frequency of a congenial group of operators known as the Straight Key Century Club. I felt right at home. I have been inducted. My SKCC number is 17272. Very QRP, don’t you think? It is almost a Vanity SKCC. Clearly, TRGHS.

I have been having excellent luck with this 7 transistor rig. I have had one contact each day since I put it on the air, all of them in response to my CQ calls. I’ve worked:

K1PUG Hank in Connecticut (twice)
W8HOG Jerry in Ohio
WA4GQG Kevin in North Carolina
WA2AAW Frank in New York
KM4FO Dwight in Kentucky


This morning I added a little piezo buzzer for sidetone. I am thinking of adding a VFO to the Tuna Tin.

The Possible Inspirations behind “Juliano Blue”

Close in color don’t you think? Dave Ishmael WA6VVL noted the NC-270 receiver’s color was “Cosmic Blue.” Indeed, National noted the unusual color (“outstandingly different”) in its advertising. This now-rare receiver was produced between 1960 and 1964, so it could have influenced Pete. Of course, the CK-722’s color could also have played a role…

BTW, shouldn’t we ask Pete to get out his guitar and give us some “Juliano Blues”? We need some music to go with the paint.

More “Canned Seafood” Homebrew CW, from KA4IBG

Bill:

My xYL hates sardines, but they look good together !
In the late 70’s the community had a fetish for canned seafood and DC receivers. Do you remember the 80m Sardine Sender ? How about YL Special ? (QST Oct and Jan 1979.) I married them together in a kludged-together box made out of a bent rack-mount panel and defunct aluminum chassis cover.
The bottom board is the rock-bound transmitter. The upper deck is the receiver board. The little mini box contains VFO (so cute.) The 741 audio board is tucked under the scrounged ¼ inch jacks.

Super simple, but lots of fun. It’s a handy rig for the week at the beach, although 80m propagation and beach week are 6 months out of phase.
Ed Hlywa
KA4IBG

Solstice Special: Midwinter BBC Messages to Antarctica
Thanks to SWL Post for alerting us to this wonderful annual event. BBC SW stations send a special program to the UK crews at the Antarctic bases. SWL Posts asks for listeners to record this year’s program:

http://swling.com/blog/2017/06/help-record-the-2017-bbc-antarctic-midwinter-broadcast-today/

 Here is an excellent recording of the 2015 show.

https://soundcloud.com/vinylzone/bbc-midwinter-special-transmission-for-antarctica-on-9590khz-21062015-21230z

And here is a recording of the 2017 broadcast:

https://ia601501.us.archive.org/30/items/BBCMidwintersDayBroadcast/BBCWorldService-Antarctic-Midwinters-Day-Broadcast-5985kHz-2130-2200-21-06-2017.mp3

Solstice Special: Midwinter BBC Messages to Antarctica
Thanks to SWL Post for alerting us to this wonderful annual event. BBC SW stations send a special program to the UK crews at the Antarctic bases. SWL Posts asks for listeners to record this year’s program:

http://swling.com/blog/2017/06/help-record-the-2017-bbc-antarctic-midwinter-broadcast-today/

 Here is an excellent recording of the 2015 show.

https://soundcloud.com/vinylzone/bbc-midwinter-special-transmission-for-antarctica-on-9590khz-21062015-21230z

And here is a recording of the 2017 broadcast:

https://ia601501.us.archive.org/30/items/BBCMidwintersDayBroadcast/BBCWorldService-Antarctic-Midwinters-Day-Broadcast-5985kHz-2130-2200-21-06-2017.mp3

A Fishy Rig: Herring Aid Five, Tuna Tin Two, VU2XVR Key

Haunted by a fear of rapid expulsion from the QRP Hall of Fame, I decided that I should immediately do something to establish some form of QRP street cred. Looking around the shack, I realized that all of the ingredients were there: My Herring Aid Five Direct Conversion receiver (completed after only 38 years), my Tuna Tin Two transmitter, the VU2XVR key that Farhan gave me, one 7050 kc FT243 crystal. I put it all on a piece of scrap plywood. A couple of nice connectors from W8NSA supported the DPDT T/R switch and the coax connector. I keep the receiver LO running all the time.

Now, let’s be clear: running 250 milliwatts, rock bound with a Direct Conversion receiver that tunes both sides of zero beat is not for the faint of heart. The log book does not fill up rapidly. But hey, I made one contact the following morning. K1PUG said I was 559 in Connecticut.

SolderSmoke Podcast #197: Farhan, Fame, ‘Fest, Testgear, SSB History, Dishal Dystopia, QRP CW, MAILBAG

SolderSmoke Podcast #197 is available:


Up in NYC, met Dave W2DAB. got Steve Silverman’s HP 8640B Sig Gen.
Farhan’s visit to SolderSmoke HQ
Got me a TEK1401A Spectrum analyzer
Farhan at “Geekfest” @W7ZOI http://w7zoi.net/Farhan-visit.html
BITX40 Modules. 5,000 already. 1,000 a month.
The BITX pronunciation problem.
QRP Hall of Fame. I suspected April 1 reprisal! “I am unworthy”
Dusting off my Tuna Tin 2, Herring Aid 5 and Farhan’s key from India.

The Manassas Hamfest: OLD crystal gear. 20’s and 30’s stuff. Leon Lambert RX and Philmore Fixed Crystal Detector.
Reminder of how YOUNG the radio art is.
RELATED: Bell System 1953 Transistor Documentary. 11 year old Pete and his CK722.
Bought some good stuff from Charles AI4OT.
Armand WA1UQO gave me a big collection of Electric Radio. So much history and HB wisdom in there. Frank Jones and Lafayette Radio. Jim Lamb and 1930s SSB.
Is the CK-722 the source of Pete Juliano’s affinity for Juliano Blue?
Was Wes Hayward already using Juliano Blue?
“Your rig sounds real good for a homebrew rig!”
“Well, your rig sounds pretty good for a Yaesu!”
Related topic: Going over the Waterfall: The SDR Superiority Syndrome. Feathering.
ARRL Arduino Book by Popiel. Very nice. Right level. Lots of good info.
BENCH REPORT:
Pete’s Dishal Dystopia — Is the perfect TRULY the enemy of the good enough?
Bill’s NE602 RIG:
Replaced OLED. Blue one seems noisier. Shielded it with copper flashing.
Made me yearn for bigger boxes WITH A HOOD!
DOCUMENTING WITH LTSPICE
MAILBAG:
Special Thanks to our correspondent in the Dayton Xenia Metropolitan area — Bob Crane W8SX.
Jack Welch, AI4SV 5R8SV — Our Man in Antanarivo — Sent me a GREAT BOOK “I, Libertine” by Frederick R. Ewing. EXCELSIOR!
Bruce KC1FSZ https://www.qrz.com/db/kc1fsz Building Scratchbuilt BITX. On the way put the VFO where the BFO should go and had a DC RX. FB
Greg, VK1VXG Suggestion for WA8WDQ on Arduino serial plotter
http://www.instructables.com/id/Ultimate-Guide-to-Adruino-Serial-Plotter/

Ben KC9DLM Mercury PTO. In a syringe! No thanks! Maybe add some high voltage and selenium. And a radium dial! Yea!
KY3R’s metalized cigar boxes! FB On Blog.
Richard WB2PEF has revived his Doug DeMaw 8P6 rig. FB. But bothered by PTT thump.
Update on Dave AA7EE (from Mike KC6SAX)

AI4OT and N2CQR
N2CQR AND W2DAB

KI6SN’s 89-Cent Project Box Chassis

Eric 4Z1UG had a great “QSO Today” interview with Richard Fisher KI6SN. Richard mentioned his method for making project boxes. The commercial versions are getting very expensive, and the used ones are now hard-to-find at hamfests. So use Richard’s technique to roll your own!

Details here: http://arsqrp.blogspot.co.il/2016/03/the-89-cent-homebrew-metal-project-box.html

FB. Thanks Eric. Thanks Richard.

Dino’s HW-8 Mods

Bill –

Enjoyed the recent Hamvention interview with Ed Hare and your comment about him and a Heathkit HW-8 QRP rig. I recently rescued the HW-8 I bought on eBay that had been sitting in my project queue for several years. As I was refurbishing the rig I found that John KC9ON (http://kc9on.com) has several HW-8 mods that are very reasonably priced and I incorporated in the the refresh. They included replacements for the audio amplifier and the T/R relay, the “miniYAK” electronic keyer that I installed internally and built-up a external control dongle for the keyer. Cleaned up the additional audio filter that the previous owner had installed (ancient MFJ CWF-2 op-amp filter, surprisingly still available from the MFJ Vectronics brand, model VEC-820K) and did a complete realignment of course. The T/R replacement includes provision for a red and green LED that indicates that the rig is in the receive mode (green) and transmit (red); I was able to mount them directly behind the relative output meter using a piece of plastic drapery hardware (always pays to keep that kind of stuff!). Finally installed a fresh S-meter mod.

RF output is ok on all the bands except for 15m and I still need to figure that out. Getting rid of the old Molex power connector and replacing it with a Powerpole was a real plus I thought. Have swapped out the PA transistor with several different types but the one the last owner substituted in seems to be the best (ECG488). Have to admit I’ve never been a devoted QRP guy but love the community for it’s technical bent but since I’ve been looking for some new challenges I thought this would be a enjoyable one.

As you’ve pointed out Mike Bryce’s HW-8 handbook is a must have for anyone updating their radio and there is also a seminal 2-part article series in CQ magazine that probably started the mods craze; they appeared in the August and October 1977 issues of CQ.

Here are some pix of the clean up process and shows I’m not afraid to drill holes in a boat anchor to make it more useable!

73 – Dino

Here’s the new audio board installed:

The additional audio filter with the new 5-pole selectivity switch put in by the previous owner…had to add some audio coupling caps and clean up all the wiring. The plastic piece over the meter was from some old drapery hardware and it now holds the RCV/XMT green/red LEDs:

I replaced the original S-meter mod with a proper terminal strip (old parts were just hanging in the air).

Here’s the solid state T/R circuit that replaced the mechanical relay:

Les Moxon, G6XN

I was on 40 SB tonight talking to Don KC5YR. He is the creator of the web site known as the Moxon Antenna Project: http://www.moxonantennaproject.com/ That site had this great picture of OM Les Moxon, inventor of the wonderful antenna that bears his name. I also found this old QSL card that shows some of Les’s homebrew gear. Les has been a Silent Key for many years now, but his legacy lives on.