Monday 1 July 2019

Building A '37-Style 'RK-39' Crystal Power Oscillator



When I completed my ‘Jones 6L6 Push-Pull Oscillator’ project in the spring, I made a start on a new ‘spring-summer radio project’ which was to be based on some 1937 RK-39 tubes that had been gathering dust here for many years.

With an unusually sunny and warm spring, I soon found that my radio-bench time was being hi-jacked with a lot of outside yard work and getting all of next winter’s firewood split and stacked away before the really hot weather arrived.

I found myself working on the project in tiny bites, sometimes not making any progress at all during the passage of a week. Headway was also tempered by the fact that I’ll often deliberate for several days over the placement of a single component or the selection of one component over another. I find this slow pace and decision ‘pondering’ during the design phase of any project to be most enjoyable as it gets my old brain working more than normal, on things that really interest me.

I’m happy to report that my latest project is now complete and fully operational and ready for operation!

As usual, I have written and published a web page fully describing the project and some of the background details of the building process.

My ‘Building A ‘37-Style ‘RK-39’ Crystal Power-Oscillator' page can be found here.

Hopefully we can have a CW QSO with it in the near future!

2 comments:

AL7JK said...

Thank you for the Qso Steve, your RK-39 transmitter has a beautiful cw note. Your signal was peaking at 449 hr in Alaska. 73 & TU om.

Steve McDonald said...

Thanks for the comments and the short QSO John! I was very surprised to get a reply from Alaska. I'm having a lot of fun with this transmitter even with the poor band condx...can't wait until winter to really give it a workout!