No power out

[ai7nn]

I have a brand new build, first time trying it out and there is 0w out on all bands. The swr will say 9.99 then nan then 1.00 and cycles through those values.

Things I have done to the RF board.
Taken out T1 and re-wound and soldered (enamel on the magnet wire was scratched up to far).
Replaced all 3 BS170 transistors.
Checked continuity of all transformers, toroids and the sma connector.

About 60 millivolts out through the dummy load when keying in CW mode.
Not transmitting in CW practice mode.



Any ideas on what I can do to narrow down where the issue is?

[DL2MAN]

Is your radio maybe in practice mode ?
Does it show T or P when you press PTT ?

73 Manuel DL2MAN

[ai7nn]

It shows R then when I press the button to key it goes to T.

[KA4LMH]

I'm getting the same issue. I do see a very brief spike of power on an external power meter that drops back to 0 in less than second.

[dl6sez]

This sounds like you are in SSB....
Think about how Single Sideband Modulation works

73 de Chris DL6SEZ

[ai7nn]

So I was in CW mode. I then switched to FM and pushed the PTT button but no watt meter or swr meter shown, so thenI went to ssb, same result as FM mode. So I switched it back to CW and tested again. Now I get about 10-12 watts out depending on band and a decent SWR. The longer I push the button though the SWR slowly climbs to 9.99 and the power slowly drops to 0.

Any ideas now? Is there a way to do a reset on the firmware and so maybe I just need a reset and reinstall firmware?

Anyone have this problem?

[KA4LMH]

This sounds like you are in SSB....
Think about how Single Sideband Modulation works

73 de Chris DL6SEZ

Excellent point, and thanks for tip. That was indeed the issue. I hadn't paid much attention to the mode. Just keyed into a dummy load after completing the build to see if the transmitter was working and it happened to be in SSB.

CW (and SSB with a little modulation) is just fine on all but 40m where I'm still getting 0 out. I'll just have to debug that band now.

[VA7RGM]

I had a similar problem. Turns out it was the relay. Listen carefully for the clicks as you change bands.

[KA4LMH]

I had a similar problem. Turns out it was the relay. Listen carefully for the clicks as you change bands.

You are correct about the relay although it was a self-inflicted problem.

Using the scope I determined that there was a good signal on LPF_OUT3 but it wasn't getting through to the ANT line through the relay. So it sounded like a relay issue alright. I took the board out of the case to further investigate and potentially change the relay only to find I had somehow missed that I didn't solder all the pins on the relay!

RF board w/ unsoldered pins

IMG_2466.jpeg (102.99 KiB) Viewed 1378 times

[KA4LMH]

So I was in CW mode. I then switched to FM and pushed the PTT button but no watt meter or swr meter shown, so thenI went to ssb, same result as FM mode. So I switched it back to CW and tested again. Now I get about 10-12 watts out depending on band and a decent SWR. The longer I push the button though the SWR slowly climbs to 9.99 and the power slowly drops to 0.

Any ideas now? Is there a way to do a reset on the firmware and so maybe I just need a reset and reinstall firmware?

Anyone have this problem?

Sorry, I seemed to have hijacked your thread with the issue I was having. I have a question about your problem though that might get yours back to the top. You said you're getting 10-12 watts out. That sounds high for this radio. Could the SWR climbing have something to do with a component heating up, given that the radio is designed for 5W? Not sure how you would get 10W out -- what supply voltage are you running?

As far as reinstalling the firmware you definitely can do that with the instructions here: https://dl2man.de/3b-trusdx-firmware/ You need your serial number, which should have been sent with the kit, in order to download the firmware. This will also let you get your callsign into the unit.

[ai7nn]

I fixed it!!!

First off let me state that the relays were clicking and I heard a click for each band I switched to. Secondly I am using a 12v sla battery. I also reinstalled the firmware, but same results after reinstall.

The issue was with T2 on the RF board. I noticed that the wire was passing UNDER the toroid, and into the through holes rather than through the toroid and into the through holes, maybe this was acting as a 1:9 rather than 1:7 transformer?