[hpsdr] Penelope output power uncontrolled

[Tokio Endo]

Hi Mike,

I measured Penelope output power on several bands. The results are as follows;

Band           PowerSdr Fwd Pwr       Measured by Spectrum Analyzer
————    ————————          ——————————
80 meters       511 mW                     27.14 dBm (= 517 mW)
40 meters       470 mW                     26.85 dBm (= 484 mW)
15 meters       483 mW                     26.85 dBm (= 454 mW)
10 meters       533 mW                     27.14 dBm (= 517 mW)
6 meters        188 mW                      23.54 dBm (= 225 mW)

Except 6 meters, the output power is not necessarily the maximum power. There would be some margins to boost more by PA Settings.
However, 6 meters band the maximum power is 188 mW(PowerSDR display) or 225 mW(measured by Spectrum analyzer and ATT).

I’m not sure about PowerSDR capability to adjust the power indication based on the actual measured power.

73,

Tokio
ja1cca

> 2019/08/09 11:09、Tokio Endo <endotokio at gmail.com>のメール:
> 
> Hi Mike,
> 
> Thank you for your comments and a question.
> 
> Yes, I looked at the URL you referred according to which I changed the orientation of T2 transformer.
> 
> You made the same modification, but the power was 0.2 watts. Here, the power is almost 0.2 watts on 6 meters band. This is not measured, but this is just on the indication of FWD Power on PowerSDR.
> I believe this indication is more or less correct. Saying that, it is needed to measure the power, and I thought I would have to do it. I will measure the power for this weekend.
> 
> My measuring is the following.
> 1) I have a 20 dB attenuator from HF to 2 GHz with power dissipation up to 100 W as well as an Anritsu 60 dB step ATT(0.1 dB step).
> 2) I have a spectrum analyzer up to 2.1 GHz.
> 3) I connect Penelope to 20 dB fixed ATT  + Step ATT, then the spectrum analyzer.
> 4) I measure the power on the spectrum analyzer.
> 
> I think the above way is relevant to measuring the power.
> When I get the figures, in other words, the difference between PowerSDR indication and my measured power, I will let you know.
> 
> 73,
> Tokio
> ja1cca
> 
>> 2019/08/09 9:59、AA8K73 GMail <aa8k73 at gmail.com>のメール:
>> 
>> 
>> My TAPR-built original Penelope had the transformer reversed.
>> I soldered the transformer in the correct orientation.
>> 
>> < http://openhpsdr.org/wiki/index.php?title=Penelope_-_Trouble_Shooting >
>> 
>> 
>> But, my power output from Penelope is 0.2 watts.  See:
>> < http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2019-April/099314.html >
>> 
>> 
>> I connected Penelope to a dummy load and used a [100 MHz] oscilloscope to measure the RF voltage across the dummy load. With the resistance of the dummy load, I could calculate the power.
>> 
>> 
>> Do you have a way to measure the output power?
>> 
>> 
>> 73,
>> 
>> Mike - AA8K
>> 
>> 
>> On 8/7/19 9:17 AM, Tokio Endo wrote:
>>> ***** High Performance Software Defined Radio Discussion List *****
>>> Hello,
>>> Today I changed the orientation of Transformer T2, the outout transformer of Penelope, like Pennylane. This is a well known fix for T2 reversal reported years ago.
>>> After this change, the output power of Penelop on, e.g., 40 meters band jumped over 600mW on the forward power of PowerSDR V.3.4.9. The power seems to be uncontrollable, but this is not identified by a power meter, but only on the screen of PowerSDR.
>>> The firmware version of Penelope is 1.8, and before doing this T2 orientation change, thais only yesterday, my Penelope worked fine except 6 meters band’s low power, only 100mW.
>>> I’m afraid this problem might be caused my soldering work on Penelope which damages some parts.
>>> Any comments would be very much appreciated.
>>> 73,
>>> Tokio
>>> ja1cca
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>