Low power out from Ameritron AL-811H Amp

JJ4SDR
Posts: 436
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Low power out from Ameritron AL-811H Amp

Postby JJ4SDR » Mon Aug 09, 2021 11:37 pm

Hi,

Again, I am shooting in the dark here as I am a complete green-horn on ANAN! :lol:

Before I transitioned over to ANAN I used my plain-vanilla Ameritron AL-811H amp without any issues and if there were any it was fairly straightforward to fix it.

Now, when I get on 40 meters the amp doesn’t put out as much power as it did in my “traditional” transceiver days. Perhaps I should use my Bird 43 watt meter and “calibrate” the 7000 DLE MKII to see if there is a difference. Normally, I use max 50 W (depending on the band) of exciter power and can easily get 600 W out on 40,20,15 and 10 meter bands. Now, I can’t.

I am barking up the wrong tree on calibrating the ANAN or perhaps there is another reason? I did notice that when I out the multimeter on “MIC” on the ANAN the peaks don’t hit 0dB as it should. Likely I need to work on that (and also calibrate the PA in the ANAN) first?

Best!
Juha
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.4.3 x64
Protocol 2 v2.1.18
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w-u-2-o
Posts: 5540
Joined: Fri Mar 10, 2017 1:47 pm

Re: Low power out from Ameritron AL-811H Amp

Postby w-u-2-o » Tue Aug 10, 2021 12:54 am

Juha,

There's not nearly enough information in your post to provide you with any real help.

What happens when you assert TUN (tune) at the same drive level you are using for normal operations?

What happens when you assert two-tone at the same drive level your are using for normal operations?

Are you using PureSignal?

73,

Scott
JJ4SDR
Posts: 436
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Low power out from Ameritron AL-811H Amp

Postby JJ4SDR » Wed Aug 11, 2021 12:28 am

Scott,

Exciting Amp with 50W from radio and when asserting TUN, I get 400W out from the Amp and when asserting the two-tone test signal I get the same 400W out (I was in the dummy load during these tests).

I don't use Pure Signal as of this writing, but will do in future.

73s de Juha
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.4.3 x64
Protocol 2 v2.1.18
User avatar
w-u-2-o
Posts: 5540
Joined: Fri Mar 10, 2017 1:47 pm

Re: Low power out from Ameritron AL-811H Amp

Postby w-u-2-o » Wed Aug 11, 2021 12:35 am

I'd suggest using another radio to drive the amp to 600W and your power meter to confirm the drive level.

Then take the same approach with the ANAN with the understanding that neither the drive control in Thetis not the built in power meter is perfectly accurate.

The power meter will be ground truth. No doubt the actual drive levels will be the same in both cases. Then you can decide how hard you want to work to calibrate everything.
JJ4SDR
Posts: 436
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Low power out from Ameritron AL-811H Amp

Postby JJ4SDR » Wed Aug 11, 2021 1:26 am

Scott,

That sounds like a very pragmatic approach. Truth be told, I think there are things that I haven't set up really correctly in my haste to jump into this exciting SDR field and I will need to devote more quality time to studying the Thetis User Guide. For instance, "Setting Up Microphone Levels!" That wouldn't impact the TUN and Two-Tone test results I would think, but if my Mic levels aren't where they should be then the PEP indications on the power meter will not "correlate" in any way to my previous experiences using the amp.

73 de Texas
Juha
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.4.3 x64
Protocol 2 v2.1.18

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