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1000W RF Output board with SWR/PWR pickup

 
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1000W RF Output board with SWR/PWR pickup
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ik0xuh
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Joined: 22 Nov 2009
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Post 1000W RF Output board with SWR/PWR pickup Reply with quote
How can help me to find the table conversion from watt and volt ?
For example with 10Watt input how many mV or Volt have on pinout of power? That is more important for me to interfacing in the correct way my PIC to view on lcd power and swr information. Many and many thanks in advance if you can help me.
All the best and have a nice day !
Sun Nov 22, 2009 5:55 pm View user's profile Send private message
pcs
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Use a SWR/power meter, observe the power and note voltage at that power
and frequency. Frequency affects readout a little bit.
Continue until you have a complete table.

Unit to unit differ a little bit due to different diode characteristics.

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Mon Nov 23, 2009 12:29 am View user's profile Send private message Visit poster's website
ik0xuh
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Post SWR/PWR RF Pickup board Reply with quote
Many thanks Marko, I will check it...
Mon Nov 23, 2009 6:51 pm View user's profile Send private message
rudirhino
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Hi guys,
I am currently trying to use one of these PCS SWR pickup boards in a MW amp I'm building. My intention is to feed the forward power signal to a peak detector circuit so I can read PEP on a panel meter. I am currently running about 250W carrier through it but I only seem to be getting about 20mV. I am measuring this with my Fluke multimeter. This seems too low for such high power. When I try and appy this to my PEP detector circuit it seems to kill it. Are the signals from this board very high impedance? I did alter the resistors on the input of the peak detector to create a high impedance input but it didn't seem to help. Any thoughts there?

One thing that might be affecting things is that I'm running the signals through about 400mm of screened cable. Also, do these boards react well to PEP?

Thanks in advance for your help!
Thu Jul 01, 2010 8:33 pm View user's profile Send private message
pcs
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Post Reply with quote
These boards are small for medium wave and will produce very low voltages. Directional couplers for such low frequencies must be longer in order to generate substantial voltage.

However for HF/VHF/UHF they are more than suitable.

They don't have PEP circuitry, you can add it externally. This is just directional coupler with detectors. PEP circuitry is not needed for FM.

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Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Sun Jul 04, 2010 1:53 pm View user's profile Send private message Visit poster's website
rudirhino
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Hi Marko,
Thanks for the info. From thinking about it since, I think the voltage I am getting could be just stray voltage into the meter. Am I right in saying that if the RF produced by each of the strips wasn't higher than the forward voltage of the detector diodes then no voltage would be seen on the outputs? I am assuming you are using diodes though and not something else.

Either way I'd say I'll have to look for a longer pickup PCB...
Sun Jul 04, 2010 11:41 pm View user's profile Send private message
pcs
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I would get a cheap SWR CB radio meter and just throw away the box.
Probably easiest way to get it.

Marko

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Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Sun Jul 04, 2010 11:51 pm View user's profile Send private message Visit poster's website
rudirhino
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Ah good idea! Thanks! I'll dig into the junk box and see what's there...

Rudi
Mon Jul 05, 2010 8:19 am View user's profile Send private message
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