[hpsdr] Penelope power output

[Michael Carey]

Hi Everybody,

I'm in the home stretch with my Codan 4404 400W HFPA project. This will 
(hopefully) get me on the air with a little more power than the barefoot 
Penelope board :-)
The 4404 amplifier dates from the 1980s where it was part of the Codan 
HF4000 series of marine ssb transceivers.

I have a question about what power output levels I should expect to see 
from Penelope.

At the moment when I press TUN with Tune Power set to 100% and 100% 
drive I can get a healthy 550mW output from Penelope.  This can 
comfortably drive my 4404 amplifier to 400W with a 10dB attenuator in 
between.  The amplifier is not rated at 400W continuous so I limit these 
tests :-)

However, the maximum output I can get on SSB with Penelope (with Mic 
input level set so Mic Meter reaches 0dB on voice peaks) is around 
100-120mW peak. With compression I can get it up to 150mW.  A TwoTone 
transmission from the Linearity menu shows 170mW peak.  A 100% AM 
carrier (no modulation) is 80mW.

The output from the 4404 amplifier with this drive is around 60-80W 
peak, quite a bit less than what it can achieve.  The input gain the 
amplifier is adjustable so I can compensate for the apparent lower SSB 
output from Penelope if needed.

Is this significant difference between 550mW 100% tune output and a 
120mW peak SSB voice signal at 0dB mic input what I should expect to see?

Regards.

Michael.
VK5LN/VK5ZEA

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