Re: PA problem on new QRSS TX.
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Hi Eddie, Yes I've adjusted the blue pot so that the unit functions on 10m but have not adjusted it for max power as the lower bands suffer. I am at a sort of half way house. I've been getting a few spots on 10m wspr today, the best being 4x1rf at 3.5k km so thats good for50mw out into a random wire. My gps unit arrived this morning but I will need to ask members for help with the pin outs. I will put that on a separate post. Thanks for your help 73's De Andy GJ7RWT
From: g3zjo
To: QRPLabs@...
Sent: Friday, May 17, 2013 3:50 PM
Subject: Re: [QRPLabs] Re: PA problem on new QRSS TX.
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Hi Andy
Have you adjusted the Blue pot on the DDS board, if you adjust for
max out on 28MHz your U2 will be stable, I am sure yours is adjusted
just on the edge.
Also I bet there is nothing wrong with the other PIC chip.
73 Eddie
On 16/05/2013 11:33, Andy Cutland wrote:
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Hi Eddie,
Mine is running on 10m ok at the moment but can be prone
to problems at startup. I found the best way to check was
monitor the swr into a known low ser antenna for the
frequency being used. If its high on startup you know
something is wrong. I am quite sure its the processor chip
not being happy at higher frequencies.
73's
Andy
GJ7RWT
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On Thu, May 16, 2013 2:39 AM PDT g3zjo wrote:
>On 15/05/2013 20:16, andyfoad@...
wrote:
>> Can't find nothing wrong.
>>
>> So I'm totally baffled as to why the amplifier is
not amplifying
>> on both PCB's ;-)
>Andy / Hans
>
>Andy have been following your woes, here, I understand
that you are
>using 28MHz. I wonder how many U2's are on 28MHz and
working.
>
>I decide to do a test for you by building up the 28MHz
LPF, too late for
>testing last night.
>
>Mine runs fine on 7MHz and 3.5MHz but set it up for
28MHz with the LPF
>in and there is no RF out and hot PA device yet the
DDS is audible on an
>RX exactly the same as yours.
>
>Andy GJ7RWT also reports "on 10m and all hell let
loose".
>
>Problem somewhere Hans? I can't think what at the
moment.
>
>73 Eddie G3ZJO
>
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