[hpsdr] Penelope Output power problem (HELP PLEASE)

[Steven Doyle]

Hi Graham, Gerd

With the board powered off I can confirm that I have continuity between JP2 
pin 1 and JP3 pin 1. When powered the voltage at JP3 is 234mVpp so it looks 
like the problem is with T3 or the DAC.

As I understand it(probably incorrectly) the DAC has a full scale output 
current of 20mA so with the 220 R7 this should give arround 4.4Vpp at the 
primaary of T3(4:1) giving arround 1Vpp at the secondary.

Measuring the voltage pp at R7 gives the same 234mv implying that DAC is not 
at full scale and also that T3 does not seem to be working(assuming my 
understanding of the transformer coupling is correct)

So what next ?

73s

Steve
G1YLB

----- Original Message ----- 
From: "Graham / KE9H" <KE9H at austin.rr.com>
To: "Steven Doyle" <steve_doyle at o2.co.uk>
Cc: "Gerd Loch" <g.loch at nt-electronics.de>; "hpsdr" <hpsdr at lists.hpsdr.org>
Sent: Thursday, April 23, 2009 12:41 AM
Subject: Re: [hpsdr] Penelope Output power problem (HELP PLEASE)


> Steven:
>
> The gain of the OpAmp output stage is about 23 dB.
>
> So for 1/2 Watt out, you need +27 dBm - 23 db or +4 dBm
> into T1 for full output.
>
> Check for about 1 Volt peak to peak at JP2 pin 1 or 2.
> Look for about 1.2 Volt peak to peak at JP3 pin 1 or 2.
>
> If not getting that, then look for problem between there and
> the DAC.
>
> --- Graham / KE9H
>
> ==
>
>
> Steven Doyle wrote:
>> Hi,
>>
>> I have done some testing and checked the following.
>>
>> Gert Build Penelope so T2 installed correctly
>> Tune Power set to 100
>> Drive set to 100
>> PA Settings set to 38.8
>>
>> The output of T1 is 236mV(Peak to Peak) and the output of the operation 
>> amplifier circuit is 2.4V(Peak to Peak)  which looks correct to me as I 
>> believe the gain is set to 10. Maybe the input (236mV) is low I don't 
>> know.
>>
>> Any further ideas or what these voltages should typically be  ?
>>
>> thx
>>
>> Steve
>> G1YLB
>>
>> ----- Original Message ----- From: "Graham / KE9H" <KE9H at austin.rr.com>
>> To: "Gerd Loch" <g.loch at nt-electronics.de>
>> Cc: "'Steve Niles'" <n5en at wt.net>; "'Steven Doyle'" 
>> <steve_doyle at o2.co.uk>
>> Sent: Wednesday, April 22, 2009 6:33 PM
>> Subject: Re: [hpsdr] Penelope Output power problem
>>
>>
>>> All:
>>>
>>> On the US built Penelope, and I assume on Gerd's Penelope, the
>>> power control loop will start to go unstable, (a very low frequency AM
>>> modulation appears on the signal) if you set the PA settings between
>>> 38 and 38.6.   This is why I recommended a PA setting of 38.8 or 39
>>> rather than 38.
>>>
>>> --- Graham / KE9H
>>>
>>> ==
>>>
>>> Gerd Loch wrote:
>>>> Hi,
>>>>
>>>> The transformer is assembled according to the errata.
>>>> All Penelopes were tested for correct output. On 6m however the output
>>>> is down to about 120 mW. This is the case for all Penelopes and is due
>>>> to the design.
>>>>
>>>> You can compensate differences in output through "PA-Settings" where 
>>>> you
>>>> can adjust the gain of the PA. That means a lower value for PA gain
>>>> result in a higher output from Penelope.
>>>>
>>>> If you set all PA-settings to the lowest gain (38) the output is up to
>>>> 500mW on 80m and slightly less on the higher bands.
>>>>
>>>> 73, Gerd
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Graham / KE9H [mailto:KE9H at austin.rr.com] Sent: Wednesday, April 
>>>> 22, 2009 2:28 AM
>>>> To: Steve Niles
>>>> Cc: Steven Doyle; g.loch at nt-electronics.de
>>>> Subject: Re: [hpsdr] Penelope Output power problem
>>>>
>>>>
>>>> Yes, if it is one of Gerd's Penelope's, then the transformer should be
>>>> installed correctly.  I guess I didn't read all the way to the bottom.
>>>>
>>>> --- Graham /KE9H
>>>>
>>>> ==
>>>>
>>>> Steve Niles wrote:
>>>>
>>>>> Surely Gerd installed the transformers per the errata... Right Gerd?
>>>>>
>>>>> Steve N5EN
>>>>>
>>>>>
>>>>> Graham / KE9H wrote:
>>>>>
>>>>>> ***** High Performance Software Defined Radio Discussion List *****
>>>>>>
>>>>>> Steve:
>>>>>>
>>>>>> Is the drive level set all the way to 100 for the test?
>>>>>>
>>>>>> Also, you need into PowerSDR under
>>>>>> SetUp,
>>>>>>   PA Settings,
>>>>>>        and set all of the PA setting windows to 38.8.
>>>>>>
>>>>>> This will usually get you up to about 300 mW.
>>>>>>
>>>>>> If you still want the full 500 mW, refer to the Errata
>>>>>> sheet for Penelope in the Support section.
>>>>>>
>>>>>> http://hpsdr.org/support.html
>>>>>>
>>>>>> This explains that you must reverse the output transformer to get the
>>>>>>
>>>>
>>>>
>>>>>> full rated output.
>>>>>>
>>>>>> --- Graham / KE9H
>>>>>>
>>>>>> ==
>>>>>>
>>>>>>
>>>>>> Steven Doyle wrote:
>>>>>>
>>>>>>> ***** High Performance Software Defined Radio Discussion List *****
>>>>>>>
>>>>>>> forgot to add that I am running the following versions
>>>>>>>
>>>>>>> PowerSDR 12Apr2009
>>>>>>>
>>>>>>> Firmware
>>>>>>> Ozy FX2:20090201
>>>>>>> Ozy 12
>>>>>>> Mercury 26
>>>>>>> Penelope 11
>>>>>>>
>>>>>>> thanks
>>>>>>>
>>>>>>> Steve
>>>>>>> G1YLB
>>>>>>>
>>>>>>> ----- Original Message ----- From: "Steven Doyle"
>>>>>>> <steve_doyle at o2.co.uk>
>>>>>>> To: "hpsdr" <hpsdr at lists.hpsdr.org>
>>>>>>> Sent: Tuesday, April 21, 2009 10:37 PM
>>>>>>> Subject: [hpsdr] Penelope Output power problem
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> ***** High Performance Software Defined Radio Discussion List *****
>>>>>>>>
>>>>>>>> Hi All,
>>>>>>>>
>>>>>>>> I just received my new Penelope from Gert(thankyou), but I  am
>>>>>>>> unable to get anything like 0.5W out.
>>>>>>>>
>>>>>>>> With the PA gain set to min (38dB) in PowerSDR and the drive level
>>>>>>>> set to 100  I am only getting 49mW out on the display when I select
>>>>>>>>
>>>> 


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