Hi,
I have heard others mention that they had low power from their Hans Summers TX. Well one my fellow QRSSers in Hamilton has that exact same problem with his 30m one(after being modified to 12v PA operation) He has some test equipment and did some tests.
The 12v modification allows for ~ 320 mW (+25 dBm) output for around 50 mA current, and he stated that he had around +150 mW (+22) about 3 dB down from expected output level.
He seperated the 1nF from the PA. Its actually 10nF or 100nF in his one. He attenuated the power and measured oiutput power from the PA without filters to be +25 dBm.(This was measured with a Spectrum Analyser, with careful verification first.
Mmm.
I had told him that the filter is essentially 3 seperate filters so he connected the input C (270pF) and L (1.1 uH) to the output C 270 pF.
Still low by 3dB.
He took turns gradually off and the power returned. He then did the same for the other coils and reconnected it up. And about 320mW, with harmonics 50 dB or greater down.
Even though the Toroid coil turns have been reduced, we suspect that they arent the problem.
We will keep you posted on the results of further tests as they come to hand
Kevin
ZL1UJG
