Amps with a PS sample Tap

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PaulManc
Posts: 49
Joined: Sat Sep 05, 2020 11:08 pm
Location: England

Amps with a PS sample Tap

Postby PaulManc » Wed May 25, 2022 10:14 am

A friend has two HPSDR radios and plans to use both independently but through an SPE V3 amplifier.

Radio 1 (Anan7000dle) goes into input1 and uses the -60db tap off the amp back to BYPASS. Output1 to the antenna.
Radio 2 (HL2) goes into input2 and uses a directional coupler xtronic on the Output2 and feeds a sample back to RX3 in the HL2

Not tried as yet BUT If radio2 is used and radio1 was switched on/off could any damage take place as I presume it will still be feeding the sample into Anan7000 :shock:

Many thanks in advance.
Paul
Manchester
K1LSB
Posts: 639
Joined: Wed Feb 05, 2020 5:25 pm

Re: Amps with a PS sample Tap

Postby K1LSB » Wed May 25, 2022 2:20 pm

Logic would suggest that if the signal strength from the -60dB tap isn't great enough to harm radio1 while it's running then neither should it be harmful when it's not running.

Mark
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w-u-2-o
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Joined: Fri Mar 10, 2017 1:47 pm

Re: Amps with a PS sample Tap

Postby w-u-2-o » Wed May 25, 2022 2:50 pm

There will be no problems with this, for the reason that Mark already gave.

Instead of what he did, your friend could very have easily provisioned a 3dB splitter (not a T, but a real, low loss, hybrid splitter) on the amp coupled output. Example: Mini Circuits ZFSCJ-2-1. There are usually lots of these, or similar ones, available on eBay for $20ish dollars, give or take. They work great. I used one to split my GPSDO 10MHz output.

Or, for a lower loss solution (because the -60dB coupling factor of the SPE amps is already 10dB too low for optimum performance) he could have used the SPE AUX connector "/EN" signals to automatically direct an RF switch to feed the amp coupled output to radio 1 or 2 as appropriate. There always lots of Dow-Key coaxial relay switches for sale on eBay for not much money.
User avatar
PaulManc
Posts: 49
Joined: Sat Sep 05, 2020 11:08 pm
Location: England

Re: Amps with a PS sample Tap

Postby PaulManc » Wed May 25, 2022 5:49 pm

Thanks gentleman for taking time out to reply, all welcomed.
Paul
Manchester

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