Heathkit DX-20

This is one I had to have, it was the first transmitter I owned.  Saw this one on eBay, no fantastic claims except it worked.  Received in mail on June 8th, 2012 and decided to give it a try, slipped in a crystal on 7.053 and tuned it up to a dummy load. Looked good so attached antenna and proceeded to call CQ, was answered by K0MSO who gave me a 449 and we finished a short QSO.  Wow! bought one that worked, 40 watts output.

Cabinet is a bit ratty looking and only one scratch on the front panel.  Didn't even bother to look inside and for now will just put it in operation in my radio shack.  One of these days I'll repaint the cabinet and take care of any minor problems I find.

 
 

(((oops!)))

Well that was a good idea, but! I decided to work on the DX-40 and not paying attention the DX-20 was on and in the transmit mode, I pulled the key out to plug into the DX-40.  While in the shop and about a half hour later I smelled smoke, entering the shack I saw smoke rolling out of the DX-20.  It was placed back into my shop on work to be done shelves and search was started to find a new transformer.  Best price I could find for a new one was over a $100.00.  I really wanted it to look like original so I just kept looking for a parts rig.

July 28th I went to the AM Get Together at KI8CQ's and found a chassis from a DX-20 which only had the power transformer, choke and some parts left.  Asked what the gentleman wanted and he said he take $5.00, gladly gave him the five after checking for that old burnt smell.

So here we go with the restoration.  A few things I would keep in mind while doing it was, needs to have fuse, new power cord and the key jack would be replaced with one that didn't close with key removed.  Why would Heathkit build it that way?  It's a CW transmitter and needs a key to operate.

 


Refurbished transformer for replacement. 



What's left of the parts cabinet after transformer removed. 

 

Started with a good cleaning getting all the tar out and removing the old transformer.  Some steel wool work and polishing.  Installed the replacement transformer, the lead lengths were way longer than I needed.  Made the changes I planed, new power cord, added fuse holder and removed the shorting leaf from the key jack.  Found a 50K ohm resistor that had been replaced with two 100K ohm in parallel, found a good one still in the junker and installed.  Also found a cleaner .1Mfd 1200V in the junker and used it.
When the kit was built, the builder didn't use short leads, so I fixed them.  did use some modern day technology and dressed things up with tie raps.  Blew it out completely with compressor and then went for the power up full test.  Put a 7.055 crystal in and ran tests to a dummy load.  Everything worked great and got 40 watts out.  

 

Someone had drilled a hole the size of a SO-239 connector and had filled it with a hole plug.  Not much I could do with that, but at least it's clean.  I looked for a matching paint everywhere I could think of, Internet and stores, but could not come up with anything in a spray paint.  I could get it reproduced at a body shop but the cost was just too prohibitive.  Finally decided that Rust-Oleum Smoke Gray was close enough, sprayed it out doors at a good distance to give it a textured look.  Put on some new feet and tucked it back into the cabinet.



 

Checked again and everything working perfect.  I never did anything with front panel and it does have some small imperfections, worst being a scratch under the Amplifier tuning that someone tried to touch up.  It's not perfect, but a very good representation of my first radio transmitter which was matched with my S-38E in 1960.  My total investment was about $65.00 and a lot of work.