some time ago I stumbled across a 'snow flake' mod for the pyrojoe 30 watt Spectrian to lift its power from 25 watts to 30 watts when used for DATV uplink.
Ok, going from 25 to 30 W probably won't make any noticeable difference - but try as I might I can't find this information.
Does anyone have a link ?
[UKMicrowaves] Spectrian 30W amp problem.
Taken from https://groups.io/g/UKMicrowaves/topics ,
the image above is re-hosted by me The text was :
Hello Colin and other readers.
I feel that I can't assist your problem any more than the help you've
already received. But I wanted to add that I do have one of these
amplifiers working perfectly well at 2403 MHz, the centre of amateur
activity here in VK.
However, I did go through the whole amplifier chain trying to find
locations for solderable tabs ("snow flaking"), hoping to make it work
better at this further-out-of-band frequency. The interesting thing is
that I did find one sensitive/responsive point and it was between the
final device and the output port, where the microstrip track takes a
left hand turn - see attached '385s image. At 2403 MHz, 10 mW input
delivered 31 Watts output following this small addition.
It was also interesting that there seems to be a layer of some plastic
material everywhere which has to be melted away before the solder will
'take' - it makes the resulting soldered joint less than good looking!
Only for interest's sake, I'm also attaching a general image of the
I wish you well with rising to your challenge!
--Doug Friend, VK4OE.
I have just purchased one of these from the seller on ebay and have measured 20W out for 10mW in on 2407.750 Mhz.
The photo attached of the PA shows that a snowflake was added at some time either on manufacture or later.
So to optimise do I move it or add another ?
73 Tony G4AXN
- cu PA stagecrop.jpg (215.25 KiB) Viewed 350 times