Loss of transmit power
Posted: 25 Mar 2023, 14:44
All:
I made several contacts with my rig, mostly on CW, and things appeared to go well. I came down several days later, fired up the (tr)uSDX and the receiver was working great. Eventually, I started calling CQ and, after about 10 seconds, the transmitter just quit and power dropped to zero. I was working 40M using an EFHW with SWR showing 1.02:1. Power out was never above 1.9W on any band, which I was willing to live with. I'm powering it from my shack's main JetStream PS (13.8V up to 30A). I tried 20M with a 1.29:1 SWR with the same results. The receiver works consistently well.
I'm really a software guy, so things like this are difficult for me to fix, although I have some fairly good test equipment (signal generator, dual 200mHz scope, DVM, etc). I've opened her up looking for bad solder joints, etc., and don't see anything on the board. I did notice that caps C10, C13, C18, C26, C34, and C39 are missing, which seems like a lot to me, but then I'm nowhere near an EE understanding of things.
If anyone has suggestions, I'm all ears!
Jack, W8TEE
I made several contacts with my rig, mostly on CW, and things appeared to go well. I came down several days later, fired up the (tr)uSDX and the receiver was working great. Eventually, I started calling CQ and, after about 10 seconds, the transmitter just quit and power dropped to zero. I was working 40M using an EFHW with SWR showing 1.02:1. Power out was never above 1.9W on any band, which I was willing to live with. I'm powering it from my shack's main JetStream PS (13.8V up to 30A). I tried 20M with a 1.29:1 SWR with the same results. The receiver works consistently well.
I'm really a software guy, so things like this are difficult for me to fix, although I have some fairly good test equipment (signal generator, dual 200mHz scope, DVM, etc). I've opened her up looking for bad solder joints, etc., and don't see anything on the board. I did notice that caps C10, C13, C18, C26, C34, and C39 are missing, which seems like a lot to me, but then I'm nowhere near an EE understanding of things.
If anyone has suggestions, I'm all ears!
Jack, W8TEE