Saturday, July 25, 2020
I finished boxing the Icom HF rig I have on eBay; now all I need to add is a label and take it to the post office.
Once I finished that task, I decided to play with my Swan 350. I had been listening to a group on 75 meters on my PROII, so once it was warmed up I switched to the Swan.
The Jackson drive on the Swan VFO needs to be cleaned and greased; the fine tuning knob slips in places when the Jackson drive gets stiff to turn. I didn’t have an appropriate pair of pliers to remove the small nuts that hold the drive in place, but will tacklet that later.
While messing with the rig and listening to the group on 75 meters, I switched it to “CW/Tune” knowing there’s no transmit. But lo and behold, I heard a heterodyne on my PRO II!
After checking my sources, I learned that you should be able to hear a low-level signal from the rig even with the final tubes out of the rig. If you do hear a low-level signal when trying to transmit, it means that all of the stages ahead of the driver and PA are operating properly — which is basically great news! This narrows my troubleshooting. The first things I need to check are the driver and final tubes; unfortunately, the tube tester I’ve had forever was soaked in a basement flood five or six years ago, and was ruined. I’m going to have to find one used — and me without a hamfest in my future!!
I haven’t pulled the cover off the Swan yet, and there are a couple of things I need to check ahead of the tubes anyway. There are a couple of relays that often caused problems with transmitting. I need to make sure they are working correctly. I need to do some voltage checks on the final tubes as well, so I have work to do before I’ll really need to check the tubes.
I have to admit that I absolutely love listening to the Swan — well, both the Swan and the Heathkit SB-102. Tube gear just has a different audio quality … or maybe its all in my head, eh??
73 es CUL … de KY4Z …. SK SK …. (dit dit)