Amplifier and TX power

[lobanz]

TrusdxAmpTunerVoltage_small.jpg (255.04 KiB) Viewed 1314 times

Playing with a little amplifier (and tuner). Max input is 5W and the trusdx triggers this every time. So I read the following threads:

• Reducing output power
• Limit power for TX

I have the trusdx power input voltage at 9V and it's making about 2.5W and the amp is making about 40W. But it still trips on other bands. An attenuator is convenient but seems wasteful (but maybe it's a trivial amount?).

I know the trusdx will safely run off USB power and make 0.5W.

My main question is how low in voltage can I safely go when powering trusdx from the main power input?

Can I power off the main power input at, say, 6V? I'm looking for safety.

Another question is about the RF sensing nature of the amp. Is this safe for the trusdx? I read that the sensing speed is about 2ms. The amp has an 3.5mm ACC input jack but I'm not sure yet if this is just for band info (supports Icom and Xiegu) or if it also does PTT.

Thanks!

--- Lobanz

[lobanz]

Any ideas?

What's the lowest safe voltage through the 3.5mm power jack?

Do you expect any problems running trusdx through RF sensing power amp (i.e., no keying interface)?

Thanks!


--- Lobanz

[VE3RRD]

Some good info and circuits for connecting an external amp in the discussion thread https://forum.dl2man.de/viewtopic.php?p=3859#p3859

[kf4hzu]

lobanz,

How has that tuner been going for you? Did you try it without the amp? I just ordered one a few days ago specifically for my (tr)uSDX and it would be good to know how it is running for you.

If you have used it without the amp does it auto-tune on USB (5v) power? Or do you need more power to trigger its tuning? My hope is USB works to limit the chance for damage to the finals during the tuning cycle.