HPSDR PURE SIGNAL

[Luca]

Hi, do you have thinked obout  to implement embedded  low power RF feedback output  for HPSDR PURE SIGNAL functionality.?

With  and external solution it will be necesary a proper coupled directional coupler.

73

IK2LRN

Milano

[WA2EUJ]

Hi Luca,

Yes, the Hardrock-500 has provisions for a low level RF tap that could be used for the Pure Signal application. The directional coupler is normally terminated in 50 ohms  on the LPF board but there is a jumper to send it to a SMA instead:

 

The output is 30dB below the amps output. One restriction is that the SMA MUST be terminated in 50 ohms for the metering and protection signal to work correctly. 

To use this with Pure Signal, put JP2 in the other position, populate the SMA and put a 10 or 20 DB SMA attenuator  right on the connector then run a cable to a bulkhead connector on the rear panel. The output will then be 40 or 50 dB below the output of the amp and the coupler will be correctly terminated. Even if the attenuator is left unterminated it presents a return loss equal to 2X the attenuation so an unterminated 10 dB pad will show a 20 dB RL to the input which is sufficient for terminating the coupler.

73,

Jim WA2EUJ

[N1IG - Anthony]

Good morning,

Did you configure your HR500 for Pure Signal?  I am interested in your results, and what attenuator and other parts you used.

Also curious, is JP2 spaced so a header pin & jumper could be used to select operation?  

Anthony - N1IG