[hpsdr] Penelope power out on higher bands

[Bruce Beford]

Bruce N1RX wrote:
> All PA gain settings at 38.8
>
> Max Penelope output with tune drive at 100 is about 120-150 mW on 6M,
about
> 350 mW on 10M. Readings from powerSDR display consistant with external
> calibrated meter.
>
> Bruce N1RX
>
>   

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Graham / KE9H replied:

"Bruce:

That is about the typical performance for a Penelope, with the output
transformer oriented correctly.  It will be about 3 dB lower with the
transformer reversed."

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Graham,

Thank you for your comments re: the output levels I am getting from Penelope
into Pennywhistle. If I disconnect Pennywhistle and measure the ouput of
Penelope directly, I can get about 150 mW at full Tune Drive on 6M. When
Pennywhistle is connected, Penelope's output drops slightly, to about 120
mW. This gives me a bit less that 6 watts from Pennywhistle at 50.1 MHz. Max
output from Penelope/Pennywhistle here is about 12.6 watts on 10M. I have
built Pennywhistle with C11=180pF. 

I expected full output to be a bit higher. I assume this will mean my linear
output levels will also be a bit lower than anticipated? I realize that
actual "on-air" signal levels may not be measurably different, but this
lower than expected output is somewhat less than was listed in the
Pennywhistle manual. (remember, I have all my PA gain values set to 38.8)
This will be a consideration when/if subsequent amplification stages are
added.

I am also very interested in any comments on my analysis of the "correct"
transformer orientation on Penelope, as it relates to the schematic. Should
the secondary be connected to the output of U6 or not? If not, then the
schematic should be updated to reflect this. (As well as AD9DP's analyisis
in "Never short a Penelope on the Wiki) Or, perhaps, I am missing something
very basic here... (wouldn't be the first time.)

Thanks again for your valuable comments, and all your great work on this
project.
Bruce N1RX