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Tuesday, December 18, 2018

All I want for Christmas is... an HT-37 L25 RF Choke-- 9 Henries at 135 ma


Following my own advice to prepare for Straight Key Night, I tried to fire up my venerable Hallicrafters HT-37 transmitter. It didn't work.  I quickly determined that none of the oscillators were working, so my troubleshooting focused on the power supply.  Sure enough, the RF choke in the low voltage power supply is open.  That's bad.  

I briefly considered giving up on this old rig.  I don't really like working with tubes anymore.  And this thing is very heavy -- a real beast.  DX-100-like in its heaviness.  It can be hazardous to your health just moving this thing around.  Opening up the case is not easy. And there are nasty voltages in there....  

But I  have had this transmitter since 1973 or 1974.  I have fixed it many times, in several countries.  I got it from a member of the Crystal Radio Club when I was a kid.   There are parts given to me by Pericles, HI8P in the Dominican Republic. I used it to transmit through Russian satellites.   That transmitter is like an old friend.  I just can't give up on it. 

So I need to replace or repair the RF choke.  Is there anyone out there who has a junker out in the garage or some other source of L25?   Or does anyone know of a business that could rewind the choke.  Please let me know.  I have decided to leave the rig on the bench until I get this thing fixed (it is too heavy to move multiple times!)   

It it Hallicrafters Part Number 056-300259. L25 -- 9 Henries at 135 ma.  Help! 

Saturday, December 15, 2018

SolderSmoke Podcast #208


SolderSmoke Podcast #208 is available: 

http://soldersmoke.com/soldersmoke208.mp3

15 December 2018

Pete and the California fires
Bill goes to Brooklyn
2 meter simplex
A return of the trivial electric motor
Audio from Mars
HF Conditions -- a real mixed bag

Pete looks back at 2018 -- The Year of the SSB Transceiver -- Lessons Learned

Hans Summers, the QSX and the virtues of SDR
W7ZOI's DC Receiver Retrospective
The 1972 Solar Flare and the Vietnam War

SHAMELESS COMMERCE:  Buy your gifts through the Amazon link to the upper right. 
Consider SolderSmoke the book as a gift.  Visit Pasta Pete's for cooking ideas. 

Don't Build It!   Sage -- but unexpected -- advice from Pete. 

Straight Key Night approaches. 

Book Reviews:  
--"What is Real?"  (Quantum Physics)
-- RHdb by K6LHA.

Movies
"Bohemian Rhapsody" 
"First Man" (Not yet!)

MAILBAG: 
Steve G0FUW
Ed KC8SBV 






Free Book! RHdb -- The Radio Hobbyist's Designbook by K6LHA

http://hanssummers.com/k6lha-design-book.html

Friday, December 14, 2018

Another AMAZING Homebrew Vacuum Tube (Valve)



I feel a moral obligation to put these projects on the blog every time I see one.  It just seems like the right thing to do.  Great work on the Pilotron.   Great workshop video also.  

Wednesday, December 12, 2018

Built-in Spectrum Analyzer in Hans Summers' QSX Rig.



I agree completely with the e-mojis.   Wow!  Cool!  I love it! 

Hans Summers is a genius. 

This is almost enough to make me get with the program and embrace SDR.  

Hans has done what seemed to have been impossible: true homebrew with SDR. 

Sunday, December 9, 2018

First Audio From Mars



How long will it be before NASA starts getting critical comments on the audio quality, along with very confident statements about how to change the audio settings on the menu?  Well, at least they have "presence."

The Elser Mathes Cup awaits a winner!   

Monday, December 3, 2018

A Beautiful Launch! Watch the Video



Today's SpaceX Falcon 9 launch of Farhan's Exseed Satellite was really spectacular. Congratulations Farhan!  Really inspirational stuff. 

Now we wait to hear the bird.   If I have loaded the orbital information correctly, I should have my first chance this evening.   I have my antenna positioned.  
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column