N6ORS and "Satan's Digital Radio"

Hey Bill,

I just finished testing the new rig.  Better sit down for this......
Its an SDR (Satan's Digital Radio). Actually its an estension of an
earlier experiment You might remember the 'Franken SDR". The Franken sdr

worked so well I thought I would make a companion for it and built a QSE 

(quadrature sampling exciter) and an amplifier chain to go with it. The rig
used G3PLX's fantastic SDRTX software for the transmit and DB0JBJ's
wonderful HDSDR software for receiving. The original idea was to make
a small rig for Digital comms, but I decided to add a Mic for voice, also
there is a 'Hardware" audio Phaser already in the building stages 

(you can calm down now).

A few specs. The RX is fantastic , -135 noise floor and the audio is
so clean that it copies wspr signals to -33db. The transmit is 

12 watts and the phasing audio sounds so nice that my wife says 

"thats your terrible voice exactly."So if you catch me on Sunday night

 and i dont sound 'yellowee' enough and you justdont like that 

no-crystal-filter sound just say  "Hey , Dont phase me bro"

See Ya on the bands,
73
Keith N6ORS

Dragnet Goes After TV Repairmen in 1951

Detective Friday goes after a vicious new kind of crime:  Crooked TV repairmen who overcharge their customers.  These monsters unnecessarily replace (or say they do!) transformers, when all that is needed is a new 5U4 tube.  Oh, the humanity!   

And the reporter they were working with pretended to be a salesman for a new company dealing in rosin-core solder!   

No kidding.  I really thought this was a joke.  They were serious.  Just click on the video above to listen.  

Or scroll forward to the 1:32:59 point on this link.  Lots of tube talk.  This one's for you Grayson!  https://wamu.org/story/18/02/20/big-broadcast-feb-25-2018/

Soldering Fingers (and SWR Bridges) in Norway

Tore Bonderudtåjet LB4RG tells us that he is a SolderSmoke listener, and that the old tradition of hams soldering their fingers together continues to be practiced in Norway.   Here are some pictures of his latest efforts.  This is an SWR bridge project.  Thanks Tore!  Careful with the fingers OM! 

N8NM's "20 Dollar Bill" DC Receiver

Steve N8NM wrote: 

I call it "The $20 Bill" because it contains about $20 in junkbox parts and complies with Bill's discreet component, hardware defined radio ethos.

73 - Steve N8NM

https://n8nmsteve.blogspot.com/2018/02/spontaneous-construction-20-bill-or-oh.html

I replied:  

Excellent Steve.   Very nice.   

Your post caused me to fire up my DC RX -- I was listening on 40 earlier today.  I think the world needs MORE 40 meter direct conversion receivers.  

Too bad about the regulator IC chip.  We need to get you an 8 volt Zener so that you can bring that receiver into a state of discrete component purity.  

DISCRETE HDR FOREVER!  

73  Bill N2CQR 

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....

HB2HB QSO with KC1FSZ and his Al Fresco Scratch-built BITX

I had some good luck on the ham bands last weekend.  First, I was called by Bruce KC1FSZ -- this time he was on his Al Fresco scratch-built BITX-on-a-board.  FB.  The next day, I called CQ on what seemed like an empty 17 meter band.  I heard someone come back -- it sounded like DX.  I had to swing the Moxon a bit -- oddly, I thought, to the south-east.  FR5FC was calling me from Reunion Island.   TRGHS. 

Here's a follow-up message from Bruce: 

Hi Bill:

Great to catch up with you on 40m yesterday.  I was using the Peppermint II which is a scratch-build of the BITX-40 for the most part, although I did my own digital VFO/BFO and made a few other modifications in order to be able to use it on 80m.  It took about 8 months of noodling to get the thing to work, but it was a great learning experience. 

As discussed, I’m working on a 24V power supply (LM723 + 2N3055) and a push-pull IRF510 final so that I can get some more power.  

I got a few more Williams-Sonoma Peppermint Bark tins off of EBay so I’m ready to start boxing things up as soon as the linear is working. 

73s,

Bruce KC1FSZ

KD4PBJ's Acorn AM Broadcast Band Regen

From Chris, KD4PBJ: 

This is my AM band regen I built during December and early January. 

It uses a 955 acorn tube and is a really hot performer! I can pick up dozens of stations with only a 20 ft piece of wire thrown out my shop window and tied to a nearby tree limb 5 ft off the ground. This is from rural Tennessee where we have no local AM’s. 

It uses a velvet vernier I bought off eBay back around 1999 or 2000 and had saved for a special project like this. 

I’m running filaments off a 6V lantern battery and plates off a type 415 45V battery. 

A nice ham/machinist I met on the Time Nuts list who lives in San Francisco made my insulated shaft couplings. I got the Delrin rod cheap off eBay. He cut them to length, center drilled for 1/4 inch and drilled each end for 2 setscrews.