"The Far Sound" -- Bell System Video from 1961 -- Good Radio History (video)

This is a really OLD video, but there is a lot of great material here: 

-- Tubes.  (Valves or Thermatrons)

-- Coax.  

-- Frequency Division Multiplexing. 

-- Negative Feedback and the fight against distortion. 

-- Transistors and early experiments with semiconductors.

-- Fiber optics and Masers.

-- Satellite communications.

-- Early hopes for video communications.

The video is, by today's standards, extremely misogynist.  And the sound experiment with the poor woman wearing a male head was just weird.   But still, an interesting film. 

Thanks to Mark KM4GML for reminding us of this wonderful Bell Labs (AT&T) video archive. 

https://www.youtube.com/@ATTTechChannel 

 

1,280 Antennas at 12 GHz -- How Starlink Works

One commenter questioned why we went with the more expensive Starlink system.  The simple answer is that it is just better, faster, and more reliable than the alternatives.  Many people here are clamoring for this sytem, and they are doing this for a reason.  On speed tests I am showing downloads of about 150 Mbps.  That is fast.  The truth is that my wife is more of an innovator than I am -- she was the one who decided on Starlink.  

When we were installing this system, I didn't even know what they meant by "Dishy."  I didn't know there were motors in the antenna.  And I certainly didn't know about the complicated software and hardware that allow the Dishy antenna to track the Starlink low earth orbit satellites without the use of the motors.   The above video explains it all very well.  

This is all a great demonstration of what can be done with digital technology, microchips, software and UHF. 

Another Evaluation of the TinySA Ultra (with Teardown) (Video)

More info on using the TinySA Ultra. 

-- Makes me wonder if it makes sense for me NOT to enable Ultra mode now.  I am not going into the UHF range.

-- Waterfall!  Sig Gen! 

-- Kerry got a lot of distortion when listening to FM broadcast signals.  I wonder if this is due to the Tiny SA detector being an AM detector? 

-- Teardown was very cool.  

-- Comparison to the HP spectrum analyser was very illuminating.  Bottom line:  TinySA Ultra gives you a lot of capability for $150.  

 

Part III: Curious Marc Repairs an All-Discrete Freq Counter: DO NOT ATTEMPT REPAIR OF CAVITY RESONATOR

I love all the "DO NOT ATTEMPT" warnings.  Wow, even HP got so skittish about this stuff.  Marc has a great sense of humor and notes that, "no cavity resonators were harmed in the production of this video."   I like the description of the mixers and the photo of the mixer antennas. 

Troubleshooting Apollo: 23 MHz Crystals in a NASA Ground Receiver

More amazing Apollo stuff from CuriousMarc. 

Here we see them struggling to find the proper frequency for one of the oscillators in a dual conversion UHF receiver from the Apollo program.  For the VCO, they needed a crystal in the 23 MHz range. They faced the same questions we face:   Series or parallel?  Load capacitance?  Fundamental or overtone? 

It just so happens that at this moment I have on my bench the 17 meter SSB transmitter that I built some 20 years ago.  And the VXO in it uses crystals in the 23 MHz range.  TRGHS. (More on the spur problem with this rig soon.  The solution does involve the 23 MHz VXO.) 

Very cool that CuriousMarc found a manufacturer still willing to produce custom-made crystals. JAN flashbacks!  LapTech Precision in Canada: https://www.laptech.com/index.php

The video above is Episode 8 in the Apollo Comms series.  If you go back one episode, you can watch Marc and his assistant troubleshoot the NASA Apollo UHF receiver.   They use very familiar troubleshooting techniques.  This reminded me a lot of what we do with older, potentially modified gear.  They were able to figure out what was wrong and  how a mod had changed things.  This set the stage for the crystal replacement selection we see in Episode 8.   Here is Episode 7: https://www.youtube.com/watch?v=87qA41A_Ies

Note:  The frequencies in this Apollo receiver were listed in Megacycles, not Mega Hertz. 

Thanks to Bob Scott KD4EBM for alerting us to this. 

JPL, Mars Helicopter, Cube Sats, Ham Radio and more: N5BF talks to Eric Guth 4Z1UG

This morning Eric Guth has a really interesting interview on his QSO Today podcast.  

Courtney Duncan N5BF had a full career at JPL and is the current president of the San Bernardino Microwave Society.  There is a lot of interesting stuff in this interview, much of it about space exploration.  Courtney tells us about how experience with re-purposing radio gear came in handy at JPL.  For example, the helicopter that they have been flying on Mars has a very cheap and light off-the-shelf Zigbee transceiver.  He also talks about the origins of the Cube Sats.   

Here is Eric's page on this interview, with useful show notes: 

https://www.qsotoday.com/podcasts/n5bf

I like to listen to Eric's shows on YouTube -- here is the YouTube recording of the N5BF interview: 

https://www.youtube.com/watch?v=Fbr4jE11vfg

Here is N5BF's ham radio web site: 

http://cbduncan.duncanheights.com/HamRadio/HamRadio.html

Here is the club page of the San Bernardino Microwave Society:

http://www.ham-radio.com/sbms/

Thanks to Eric and Courtney! 

Opening up an Apollo Command Module Microwave Radio System

So much radio goodness in this video.  The enthusiasm of the narrator is unmistakable, and entirely justified. 

A number of things struck me: 

-- Nice shout out to our beloved Parkes Radio Telescope, of  "The Dish" fame. 

-- I like how the French narrator takes some friendly jabs at out use of "archaic British measuring units," and his skillful use of American slang" "Let's open up these bad boys!" 

-- Wow, they filled the radio cases with Nitrogen!  That will definitely save you  money on De-Oxit! 

-- When they opened up the boxes, the construction looked very similar to what I found inside my HP-8640B frequency generator.   

-- Collins built some of this stuff.  

-- 11.6 watts to transmit the TV signal from the moon. 

-- PLL.  

-- A tube type amplifier.  

--- Lots of SMA connectors, but many BNCs also, right? 

-- Finally, and this is really amazing:  THEY HAD A MORSE KEY WITH THEM, JUST IN CASE. 

Thanks a lot to Bob, KD4EBM for sending this to us.  There will be more episodes.  These guys intend to fire up the equipment. 

Jenny List's Favo(u)rite Things

Over on Hack-A-Day Jenny List (G7CKF)  has a really nice article about ham radio and homebrewing.  She truly has The Knack:  She got her start in radio electronics at age 9 when her parents gave her George Dobbs's Ladybird book.   

https://hackaday.com/2021/01/21/a-few-of-my-favorite-things-amateur-radio/

One of her paragraphs really seemed to capture the SDR-HDR conflict that we so often joke about: 

The age of the homebrew RF tinkerer may be at a close, at least in the manner in which I started it. Nobody at the cutting edge of radio is likely to be messing around with discrete transistor circuits in the 2020s, unless perhaps they are working with extremely exotic devices up in the millimetre wavelengths. It’s all software-defined radios, opaque black plastic boxes that deliver a useful radio experience on a computer but that’s it. No more homebrew, no more tinkering. 

Whew, good thing I'm not on the cutting edge.  It sounds kind of sad.  Oh well, that leaves more discrete transistors for us to tinker with.  

Jenny's Profile on Hack-A-Day: 

[Jenny List]: Contributing Editor and European Correspondent

Jenny List trained as an electronic engineer but spent twenty years in the publishing industry working on everything from computer games to
dictionaries before breaking out and returning to her roots.

She grew up around her parents’ small farm and blacksmith business in rural England, so making (and breaking) things is in her blood. Countless projects have crossed her bench over the years, though these days you’ll find her working with electronics and in particular radio, textiles for clothing and costume, decrepit classic cars, and real cider from first principles.

When she’s not writing for Hackaday she works on language corpus analysis software, designs and sells amateur radio kits, sits on the board of Oxford Hackspace, and is a freelance electronic design engineer and programmer.

• Hackaday Articles
• Hackaday Profile: Jenny List
• Twitter: @Jenny_Alto
• Personal Website: Language Spy

Thanks Jenny! 

Listening in on the Deep Space Network

 

Not long ago we took the DISH satellite antenna off our roof.   For a while I resisted pleas to put the big thing on the curb for pickup.  I fantasized about using it for radio astronomy.  In the end, I threw it away.  I do have VHF/UHF aspirations, but being able to use that dish just seemed to be something in my distant future (if ever!).  

But check out what David N2QG is doing with his dishes:  He is listening to very distant spacecraft normally picked up only by NASA's Deep space network.  Very cool.   Truly inspirational.  

Here are the links: 

http://www.prutchi.com/2020/10/15/recap-of-x-band-dsn-activities-and-plans-for-the-future/

http://www.prutchi.com/wp-content/uploads/2020/10/DSN_Lessons-_Learned_N2QG.pdf

NanoVNA, Millen Dip Meter, Kilo-Megacycles, and Measuring the Speed of Light (Video)

Yesterday my NanoVNA arrived.  This morning I was looking for info on how to use it and I found this really wonderful video from Joe Smith.  

Wow.  Joe gives a really useful intro to the capabilities of this amazing little device. He even reaches back in time and compares NanoVNA results with those obtained by a Millen Grid Dip Meter.  He pulls out of his junk box an attenuator that is so old that it is marked in "Kilo-Megacycles."  (Shouldn't we revive terms like that?)

Joe also gives us a taste of what it is like to live and work in the GHz range.  He warns us never to touch the SMA connectors on our NanoVNAs (too late Joe).  And -- get this -- he uses a torque wrench to connect the little SMA coax connectors to the NanoVNA.  I'm not kidding.  A torque wrench.   Joe connects surface mount capacitors and inductors that have their values specified not only in picofarads and microhenries, but also at the specific frequency at which they were measured.  

My understanding of the Smith Chart was greatly improved by watching Joe's video. 

Icing on the cake:  Joe wraps up the video by using the NanoVNA to MEASURE THE SPEED OF LIGHT.  Great stuff.  Thanks Joe.  

Here is Joe Smith's YouTube channel:  
https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg

Now I have to get the software to use the NanoVNA with my computer. 

A Wonderful Troubleshooting Story -- Thailand, Mixers, a Simpson 260, Microwaves, and some Black Tape

My old friend was really fortunate to have had such a good Staff Sergeant instructor at Signal School, someone for whom the mixer trig was obviously not enough.  And our old friend obviously also benefitted greatly from having had a dad who set him up with a Simpson 260 and some handmade experimental glass diodes. Wow.  It all came together with some black tape in Thailand... 

Bill,

Enjoyed your latest blog. I remember your asking about mixers years 

ago.  I received much the same explanation from a Staff Sergeant 

instructor at Ft. Monmouth in 1967.  His example was a mixer with 

diodes, noting the need to have them forward biased by the LO supply.  

We worked out much the same waveforms as shown in your Blog and 

the concept became part of my 'intuitive' knowledge.

A few years later I was fighting 120hz hum on the baseband of an IWCS 

microwave system feeding USAF command at the Korat Air Base in

Thailand. The hum was pretty high level and causing inter-modulation 

problems on the 60 channels of signal sideband suppressed carrier 

being applied to the microwave system.

We ended up with a couple of DCA DoD employees being flown in to help, 

to their credit they were prior service and darn good at what they did.  

After three days of testing all parts of the microwave system with a 

very long distance and long duration phone call to the manufacture in 

Calif, they still had not found the trouble.

I had stayed working with the DCA guys all of the time, during the 

testing I noted the hum seem to lessen in strength with someone standing 

directly behind the radio bay.

I went around to the back and took a close look, Yep! the mixer diodes 

for the baseband order-wire were glass and exposed.

Put a length of black tape over them and the hum went away.  Not the 

power supply problem everyone was fixated on, it was diode photo 

sensitivity.  I guess we could have just turned off the florescent 

lights too.

When I was 10 years old my father showed me how to use a Simpson

260 to check diodes and early transistors*. We were on the floor of the 

living room with sunlight streaming in.  I saw the forward resistance change

a lot when the glass diode was in sun light vs shade. It was this memory 

that prompted me to try the black tape.

All the MW systems in SEA later received a MWO to change out the 

order-wire board and I found that the assembly was a non-standard part 

of the microwave system just for military use.  Civilian deployment of 

that microwave system had no need for the order-wire.

Thanks for the quick trip, for me anyway, down memory lane and the 

memory of being an electronics tech hero for all of two minutes. The DCA 

guys made me buy the first round at the club.

73  from an old friend....

Towers and Antennas in Church Steeples and on Mt. Washington (VIDEO)

VK3YE QRP by the Bay Goes VHF/UHF

Peter Parker again hosted the VK3 radio amateurs.  This time the event fell on VHF/UHF Field Day weekend.   So Peter and his friends went up in frequency and up into SPACE!  

VK3HN has a nice blog post here:

https://vk3hn.wordpress.com/2017/11/25/qrp-by-the-bay-chelsea-beach-melbourne-25-11-2017/

Be sure to read about Peter's ankle manacles -- he apparently uses them to get a good ground (sea) plane while running pedestrian mobile on the sea shore. Peter is DEDICATED! 

More on GM3OXX

Sunset at Luce Bay Scotland, 3cm GM3DXJ, GM3OXX and GM8HEY dishes being set up. Photo GM8HEY (GM4JJJ). 322 km QSO to Wales. 10mW GUNNS WBFM.

Bill,

Thanks again.

I recall when George met up with the team from Wales in a car park in the Scottish highlands , they had also built 3cm gear and he found by direct comparison that their 3cm gear was more sensitive than his. He went straight home and redesigned and rebuilt his receiver. That gear then went on to break the World distance record on 3cm on a superrefraction path from Portpatrick to Cornwall with 10 mW WBFM. Smashing a record that the USA had held for 16 years from mountop to mountain top.

George was ambitious, he wanted that UK, EU and World distance record, he wanted to show the RSGB that Scottish hams could get the 3 countries and 20 counties award on 3cm. We  (G8BKE, GM3DXJ, myself and George) did it by travelling round Scotland in my Mini Clubman Estate with dishes and tripods and 3 hams packed in to one car, at the same time fitting in the EU distance record from Luce Bay in Wigtownshire to St David's Head in SW Wales at 322 km just to show them how.

No VHF Talkback, only a phone call from a telephone box earlier in the day to our Welsh counterparts to say we would be there about 6pm and to tune the 3cm band for us. Frequency uncertainty was in the 10's of MHz.  We arrived at the beach, set up 3 dishes, put on our transmitter test tones and then went back to receive, George asked us to make sure we had our test tones -off-  as his receiver was overloaded, it was the Barry Radio Guys he was hearing, they were so strong. Didn't matter where we pointed the dishes, we were in the sea level duct. Open waveguide still full quieting.

George's words audible on the remote tape recording made in Wales, " You can pack up your gear now lads, that's the European Record!"

Happy Days!

-- David GM4JJJ

GM3OXX SK

Bill,

I expect you will have heard via the grapevine, George Burt GM3OXX is silent key. Bad news travels faster than light.

I knew George GM3OXX before I was even licensed in the 70's, as I heard his broad Scottish accent on 2m AM when he was portable on a local hill and was using 2m to set up 3cm contacts with QRPp WBFM. I climbed the hill and introduced myself and he graciously answered my questions. 

George didn't drive but despite that was able to climb all of the Munros (summits over 3000 feet) in Scotland and operated on 2m from all of them. He used hitch hiking and buses or bicycle to get to foot of the mountains. 

Fast forward a few years, I had my first ticket GM8HEY...

I spent a night in my grandfather's ridge tent on top of Snaefell (the highest mountain in the Isle of Man) (GD) with George. We had planned to take my car to the island by ferry, but had not realized that the TT motorcycle races were on and the Ferry was fully booked. We had to go as foot passengers and reduce the amount of gear. George carried his tripod and dish, 3cm and 2m gear and antennas plus rations etc, I carried this huge ancient canvas tent with wooden poles and pegs. We got to a campsite and we were told it was full, when we asked where the next site was the owner asked us where our motorbikes were, we explained we had come by foot, so he let us pitch our tent after all as we weren't bikers.

George originally had planned to climb the mountain by foot, but with this huge tent even though I was fifteen years younger than George I would never have made it, so reluctantly we took the mountain railway which goes nearly to the summit of Snaefell. 

The previous night it had snowed on the mountain, fortunately it was just freezing cold and windy when we camped right on the top. We had to use rocks to try and hold the old ridge tent down, it had no built in ground sheet. George's "rations" seemed to be a bar of chocolate and some tea that he boiled on a tiny stove powered by some little pebble sized block of flammable material. I have never been so cold and hungry after a night in a sleeping bag. We idled some of the time calling stations on 

2m with George's homebrew 2m battery powered transistorised transceiver.

Next morning it was too windy to set up the dish and tripod, so we assembled it -inside- the ridge tent and successfully operated from there on 3cm WBFM across to G, GW and GM. on 10mW QRP of course.

George went on to break UK and EU distance records on 3cm before packing microwaves in and going back to QRP on HF. 

George was as fit as a mountain goat in his youth, tragically he was struck down with a terrible condition in early middle age that robbed him of his strength and ability to even walk, let alone climb mountains, but you wouldn't have known it, he never complained, just the same old George "building wee boxes" as he put it to me on one of the last times I spoke to him. 

If you visited George's shack, you wouldn't find any commercial gear at all, everything he built himself, it was so beautifully made too, I marvelled at how compact and neat it was. 

There won't  be another George Mary Three  O Ocean  X X-Ray  X X-Ray on the bands.

Thanks for all the great times George, I am sure you won't be resting, you are probably designing that next "wee box".

-- David GM4JJJ

SolderSmoke Podcast #198 - D-104, HW-8, Juliello, DIFX, Dishal, Baofeng, MAILBAG

Bill Breshears WC3K (SK)

SolderSmoke Podcast #198 is available. 

http://soldersmoke.com/soldersmoke198.mp3

29 July 2017

Sign on a beach store:  SHACK-TACULAR! 

Noticed that EB63 amp was getting hot. Why?  

TT2, Herring Aid5, Farhan's Key:  QRPp and CW!  See?

D-104 lore -- Reading from Bill Breshear's (WC3K) ER article

Astatic  crystal/ceramic element -- disappointingly flimsy

Electret-ing it.  The G-Spot (see picture above)

Walery KB2FIV sent crystal mic element and piezo buzzer (reverse for mic!) FB

HW-8 AF filter Center Frequency Problem.  IT'S TRUE!  Fixed!  Finally. 

Shack re-org at N2CQR

Got Steve Silverman's HP 8640B Sig gen on the bench.  Required reinforcement

Pete's new DIFX

LM373 rigs.  Perhaps with that CA3020 Pete sent me. Chips Ahoy! 

Juliano Yellow? Origins of Blue?  Juliello? Julionyx? 

HB Crystal Filter Capitulation? Don't give up Pete --  just dish the Dishal!

Ceramic VXOs?  K.P.S. Kang

Crystal testers by G7WKE and Dino KL0S.  Impressive. 

Antennas and BITX40 modules.  Antennas are important.

Bill's new Baofeng HT on 440.

Fixing my Sony SW7600GR

MAILBAG

Steve Silverman alerts us to NYC radio row now in the Bronx.

Tony G4WIF on the cover of SPRAT -- Getting the Don Cameron award. FB 

Armand WA1UQO points out that the Berryville hamfest is coming up... 

Thomas KK6AHT F4HDQ writes in. 

On the air with W8NSA

Juliello.  No. 

And Now For Something Completely Different: 70cm FM

So there I was, talking to KE5FV on my scratch-built 17 meter BITX, when in walks my son Billy with this walkie talkie.  "Hey Dad, I'm cleaning out my room -- could you use this?"  I'd seen it before but I thought it was some Family Radio Service device that he had picked up.  But no!  It is one of those very cheap Baofeng UV-5R FM transceivers.  I soon found myself scrolling through menus, trying to figure out how to use the strange new appliance. 

I got it on 70cm and soon established contact with a Bill W3HXF -- that was my first ever UHF contact.  We then switched to 2 meter simplex. 

It works fine.   I've been looking for something different.  This could be fun.  Any suggestions on how to make the most use of this thing?