The Spectrian Amp for 2.4 GHz

[VK3QI]

Tim,

I see that you left the snowflakes on the inputs to the two finals.

That seems to be the biggest variation from board to board, often with a snowflake on one side only - perhaps this is the critical adjustment to get proper sharing of the load.

The little trimmer on the left hand side at the input to the left final must play some part in the final balancing adjustment as well.

Cheers

Peter VK3QI

[VK7HH]

What's the maximum input power for these boards?

I don't think I am saturating as I have 2.2W out of my transverter. With a 3dB attenuator on the output of the transverter I lose about 1.5dB of output power from the amplifier. Pyro only specifies "input drive required for 75W output power is 1.25W".

[VK2XAX]

What's the maximum input power for these boards?

I don't think I am saturating as I have 2.2W out of my transverter. With a 3dB attenuator on the output of the transverter I lose about 1.5dB of output power from the amplifier. Pyro only specifies "input drive required for 75W output power is 1.25W".

Looking at the data sheet for the XRF286 it has a gain of approximately 10.5dB.

Given their function tests show an output of 60W CW this means that the input power was around 5w

47.78dBm - 10.5dBm = 37.28dBm = 5.34 watts @ 26V and IDQ of 500mA

So I don't think 2.2w is going to hurt it.

cheers
Tim

[VK2BLS]

I have just completed my Spectrian 30W PA unit with SGLabs 13CM transverter. (not the 75W unit)
Big thanks to Rob VK1KW for info on where to source PA and bits and pieces needed to configure.

73 Darrell vk2bls

[VK7HH]

Excellent looking build there Darrell.

Any particular reason why you've used dual relays and not split the RX and TX in the transverter? I split mine off to simplify things and eliminate that extra relay.

Hayden

[VK2XAX]

I have just completed my Spectrian 30W PA unit with SGLabs 13CM transverter. (not the 75W unit)
Big thanks to Rob VK1KW for info on where to source PA and bits and pieces needed to configure.

73 Darrell vk2bls

Very nice - you need to point your beam up here, we should hear you quite well now

[VK4CZ]

Great job Darrell... you'll be sought after by the SYD guys now