SolderSmoke Podcast

SolderSmoke Podcast # 250
February 10, 2024
Welcome to Dean KK4DAS. For 2024 Pete and I hope to jazz things up a bit by bringing in fellow homebrewers to talk about their projects. Dean is our first victim. Welcome Dean.
Some good news: Several new homebrew receivers are inhaling: Armand WA1UQO in Richmond has an amazing looking regen. Scott KQ4AOP in Tennessee got his DC RX working. Mike AG5VG in Texas has been homebrewing BITX 20s and BITX 40s. All are on the blog.
Pete's report:
--- Recent blog entries on filters, SSB rig architecture, and of course digital VFOs.
-- Phasing measurements, quadrature, and the Seeed Xiao RP2040
-- Error in QST article on early SSB transceiver. ANOTHER ERROR!
--LC VFO on blog! FB Pete!
Dean's report:
-- Tales of woe on the homebrew sBITX
-- Help from Farhan.
-- Ground Bounce. FFT Hallucinations. Wisdom files.
--Great background info on Dean's homebrew sBITX:
kk4das.blogspo...
SHAMELESS COMMERCE DIVISION:
-- Whenever you are tempted to buy something from AMAZON, just start at the Amazon symbol on the right side of the page. We get a cut from Bezos, and it doesn't cost you anything.
-- You can try to do the same thing with E-bay. We are finding a lot of great parts there.
-- If you see us posting on Facebook, please Like it and Foward it. This helps us.
-- Become a patron! Go to the Patreon page. We put the money to good SolderSmoke use.
-- Visit Mostly DIY RF and buy a PSSST kit!
Bill's bench:
-- Building yet another BITX dual bander. 15-10 again. Tried to use a 25 MHz filter left over from the earlier project, but I had to build another. Built a new VFO using the variable cap and anti-backlash gear recommended by Pete. Was a bit tough to get the receiver sounding good. Had a diode ring as the second mixer, but went back to a singly balanced mixer. Still working on it.
-- 10 meter AM -- Thanks to Jerry Coffman K5JC for mod.
Other topics:
--Counterfeit chips. Why?
MAILBAG:
Wes W7ZOI
Jim Cook W8NSA Transoceanic BFO
Grayson KJ7UM -- Vintage Computer Museum
Chuck Adams --Glad to hear that Chuck is doing well.
Frank Harris K0IYE -- NO CHIPS!!!!
ED DD5LP Antenna software
Eldon KC5U 10 AM We made a contact
Joh DL6ID 10 AM
Phil W1PJE of MIT 10AM Where is L5?
Bob WP4BQV now in UK
Dino Papas KL0S in Wilmington Reverse Polarity protection.
AA7EE Dave Richards Liked Armand's receiver
Rogier PA1ZZ
Jonathan-san W0XO Listened to my ET-2 CW Whoop,whoop
Nick M0NTV Great videos from Nick the Vic
Will KI4POV Working on his own SSB rigs.
John West -- Who is the South American ham who made his capacitors and heat sinks?
Ed KC8SBV Working on DC receiver, experimenting with FETs
Nick N3FJZ -- watch out for dead bands when testing receivers!
Don KM4UDX encouragement from new Prez of VWS
Dave K8WPE Likes QF1 Cap backlash. Says I'm getting soft!
Dave WA1LBP My fellow Hambassador, from Okinawa USMC Sergeant with a workshop.

[@Northern-Rambler]

Brilliant as always guys, nice to see Dean on the show.

[@Circuit6040]

WOW! This was a great episode, having Dean there was a real treat! Dean, come back again soon. It would be nice to hear more in the future about homebrewing the sBitx; e.g. part sources and part numbers for the more critical parts (Mouser or DigiKey # for crystals, codec board source et cetera), step by step how-to on building and uploading the sBitx code collection to the Raspberry Pi. The details could be covered in detail on Dean's blog with highlights mentioned on the Soldersmoke blog to generate excitement . 73 Rick N3FJZ.

[@frankjames264]

Fantastic show! The first ham radio signals I heard were on a homebrew receiver as well... NE602 direct conversion.

[@trevorwoods3367]

Great video. Good to see Dean on there.

[@michaelrogers3078]

Great as always. I like Dean being part of the team. Will he be a regular? 73 Michael N4MJR

[@migalito1955]

Cool beans, guys. I still aim to build your direct conversion receiver. I only at the moment have & had internet via cellular service at a limited speed & its a bit iffy at best. This has slowed me down, but hope is in sight for good internet service in this very remote area of the Catskil Mountains of NY. In rhe mean time I have under construction a regenerative receiver to replace the one I built 15 years ago on a pine board using copper brad nails as the solder points for the components. It was surprisingly decent for a first time ever receiver, but I really want to understand the method of receive via direct conversion, hence it is on my list for sure. Always enjoy your chats.....

[@migalito1955]

Cool, 1st comment. Now I have to type something meaningful, Ok: Thanks, Bill, Pete, Dean. Your sharing is simply invaluable....

[@M0NTVHomebrewing]

Great podcast and lovely to see Dean as well. 73 Nick M0NTV

[@4youian]

Big fan of the show! Skyworks is not the only source of the Si5351. They are also available from China with part MS5351M. They work great too (sorry about that). Cheers, 73, VK7IAN

[@PapasDino]

Always learn a couple of new things with every podcast, thanks guys! 73 - Dino KLØS

[@edbeckerich3737]

Somebody else engaged in this lunacy!!! LC VFOs, ha ha ha yes, it's fun!! Ed KC8SBV

[@AA7EE]

There's not much in this world that is more pleasing than a stable free-running LC VFO! Todd VE7BPO (the author of the excellent QRP Homebuilder blog) detailed how he built an LC VFO on 7MHz in a diecast case, that drifted less than 5Hz/hr. Fantastico!

[@feltusfeicit]

I have been told that Intel still does *that*, in the sense that a Xeon, i9, i7, i5 and i3 may come from the same wafer, but they pass tests at different specs. To me this makes digital processors very confusing, because it seems like they have an organic element to them, a presence that they don't really have.

[@radiotec76]

Bill, so far my Herring Aid 5 oscillates but it’s a bit deaf. The audio was really deaf but I changed out the coupling cap between Q3 and Q4 then it would go into oscillation but fixed that by replacing the other 40 year old emitter to ground caps. I ran a noise bridge to the Herring Aid 5’s front end but doesn’t null out at 50 ohms or at all. It does seem to receive a signal when tuned in but the audio is still weak. I suspect the problem is between the front end and the mixer. Investigation continues. Rick, WD5L

[@soldersmoke]

Experiment (a lot) with the coupling link from the VFO to the mixer. You may have to reduce the level of coupling. Are you sure VFO is in 40 meter band? Check. To see if AF amp works, touch finger to base of AF amp input transistor. You should hear a buzz. To test bandpass filter see if you can get it to peak on a 40 meter signal. Or one close to 40. Like the broadcast stations just above 7300 Elon the evening. Hang in there.

[@radiotec76]

@@soldersmoke it’s in the 40 meter band. I can hear it on 40 from my Sony ICF-2010 with no direct connection. My HP frequency counter confirms it. I am also getting audio from the audio stages. The hiss noise goes from nothing to loud when I turn the knob from fully counter clockwise to clockwise. I injected audio from the final audio stage back and I hear audio. I will try the LO coupling to the mixer. I think I should check the transformers before the mixer.

[@soldersmoke]

Sound like the AF amp is working. And it sounds like the VFO is working. But again, make sure you are getting the right amount of VFO RF to Q2 from L5. Yes, check the RF amp and the transformers. What kind of antenna do you have? Remember that 40 goes dead around mid day... 73 Bill

[@justinelliott3529]

I just got my 40m superhet to “breathe” as you say. I’d like to some pics and videos. AC8LZ

[@soldersmoke]

Great! Send details, pictures and videos: [e-mail] Thanks 73 Bill