UHF Connector PL-239 / How to connect it to the pallet amp?

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honsey
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UHF Connector PL-239 / How to connect it to the pallet amp?

Post by honsey »

Hi there,

a while ago I built a low power fm transmitter with a microcontroller controlled fm exciter. That feeds into a PCS 25W pallet amp and a filter.

It was my very first UHF project and I think (I know) I made a lot of mistakes...

Here's a picture of the open casing (connection exciter pcb <> amp removed):
Image
(The colored wires are for the lcb display and buttons on the font panel.)

Now I want to improve some aspects. I made pictures of the current setup. Maybe you can suggest how to do it the right way:

1) Connections between Exciter PCB<>AMP<>Filter. I used RG-178/U 2mm TEFLON brown and soldered it directly on the PCB
Image
Image
I think those are okay, as I see not much of an alternative to that. (And the silkscreen on the pallet and the filter suggests a connection like that...)

The connection from the Exciter to the AMP is really really "hacky".
Image
I thought about placing a SMA or U.FL connector on the PCB and an SMA connector on the AMP. Then connect both with a prefabricated cable. Do you think this is a good idea, or would I loose too much dB? (Given the fact, that I would layout proper solder pads on the next PCB.

2) Connection between Filter and PL-239 case socket. I used a thicker cable that is (I think) silver coated, can't remember the exact product name.
Image
Very very improvised, i know. I am very interested in how would you do this connection "right". Help! :)

It's working fine – could measure about 20W output with a cheap SWR-Power-Meter.

Now I want to build another one and do it better this time. Hope you guys can give me some tipps where to improve.


Thanks in advance + Have a good one,
Hans
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pcs
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Post by pcs »

You did good with this connector, however you could add more ground leads from other screws to reduce ground terminal inductivity.

To do better:
http://www.pcs-electronics.com/panel-mo ... -1688.html
N female flange for RG142 or .141 semirigid - easy install

Now this connector brings ground all around your coax so connection is really perfect.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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