[hpsdr] Penelope power output

[Michael Carey]

Hello,

Apologies for not getting back to this sooner.

I'm using an OZ2CPU clone wattmeter.  This is a QRP meter that will 
handle up to 1W input barefoot, it uses the AD8307 Log Amplifier.

It does have a "SSB PEP" mode.  My Penelope has transformer T2 in the 
correct orientation.

Since my original question, I have done some more experimenting.  I have 
set each bands PA gain to 38.8 dB. At this level I am finding that a 
Tune Power Level of 10 gives me 100mW out up to 50 with 500mW out 
(within 2%).

SSB voice peaks from Penelope are 250-260 mW with my Mic Gain set to 
6dB.  When I turn Compression on, I can make the peak levels rise into 
the 300-350 mW region while not exceeding 0dB on the Compression meter.  
I am using a Shure SM48 Microphone with a single transistor amplifier 
PCB salvaged from an old Philips FM900 microphone.  This amplifier is 
powered by the Electret bias voltage from Penelope.

I can easily get my 400W PEP output (from 160m-12m) from my Codan 4404 
amplifier with these settings by adjusting the amplifiers internal gain 
and ALC trimpots.  I set Tune Power to around 3-4 which then gives me 
50-60 Watts of tune out of the amplifier in the High Power setting.

The amplifier has a High, Medium and Low Power setting.  Medium is 80W 
PEP and Low is 10W.   I have to be careful with carrier modes (like AM) 
as the Codan 4404 will dutifully output a 400W AM carrier (which is it 
NOT rated to do and it gets quite hot VERY quickly, it is most certainly 
a SSB amplifier).

At this stage I am happy with how it's working.  I have also just added 
a relay to terminate the RX line from the 4404 Amp to Mercury into 50 
Ohm when transmitting.  There is not enough isolation in the 4404 TX/RX 
relay. I get ADC Overload on PowerSDR flashing on voice peaks while 
transmitting. I don't want to kill my Mercury board! :-)

73

Michael.
VK5LN/VK5ZEA

On 11/08/2020 3:18 pm, Helmut Oeller wrote:
> Hi Michael,
>
> what kind of meter you are using to measure PEP power? Seems that your meter
> can't indicate PEP. Recall 500mW carrier or PEP are equal 2 x 125 mW
> 2-tone-carriers.
> I've no doubt that your Penelope is working fine.
>
> 73, Helmut, DC6NY
> -----Ursprüngliche Nachricht-----
> Von: Hpsdr [mailto:hpsdr-bounces at lists.openhpsdr.org] Im Auftrag von Michael
> Carey
> Gesendet: Dienstag, 11. August 2020 06:16
> An: hpsdr at lists.openhpsdr.org
> Betreff: [hpsdr] Penelope power output
>
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>
>
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