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Vhf Micor PA Question
Posted: Wed Dec 28, 2005 12:54 pm
by tkiuntke
Hi guys, I have a Micor VHF 100 watt cont. duty PA (TLD1690 series). I need some help figuring out what a couple of the off-board parts are. Specifically, there are three components mounted on terminal strip next to the Power Control housing. It looks like one is a cap one is a coil and one is a cap or resistor. They are on the A+, A-, and power control lines from the PA to the power control board housing feed thru caps. I simply cannot find them referenced in my documentation and I would like to ID them since this is the only thing standing between me and getting this PA going. Thanks in advance for any help you can give.
Toby Kiuntke
KC0FRU
Posted: Wed Dec 28, 2005 1:56 pm
by Will
That should be the decoupling for the DC to the PA.
You still have to have the power control circuitry for it to work.
You can check on repeater-builder.com there are some good articals on the MICOR's.
Posted: Wed Dec 28, 2005 2:12 pm
by tkiuntke
It's actually on the three wires that go to the power control board thru the feed thru's on the metal housing around the Power Control board. Everything else is there but these three parts and the terminal they were soldered onto. These are the parts that let out the magic smoke and now I can't get it going without robbing one set from a good PA.
Repeater Builder didn't have this specific info. (sorry)
Anyone?
Posted: Wed Dec 28, 2005 3:10 pm
by Will
Again these are decoupling componets.
A+ goes thru a 8.2 ohm res, a .62uh choke with a 10uf cap to Keyed A-.
Then to pin 1 on the power control board.
Keyed A- goes thru the feed thru and to pin 2 on the power control board.
Power control, blue, goes from pin 3 to the PA. The power control transistor may be in the PA chassis, and is a NPN, emitter to A-. A TO220 on the chassis.
Posted: Thu Dec 29, 2005 7:50 am
by tkiuntke
Thanks Will!!! Thats exactly what I needed. I realized you were right about the DC decoupling, I just needed the component values. BTW what type of cap is that, and is it 35V or more?
Thanks again, I really want to get this PA going.
Toby
Posted: Thu Dec 29, 2005 7:39 pm
by Will
According to my book the resistor is 8.2 ohms, 1/4 watt
The cap is a 10 uF 20 volt electrolytic so a 25 volter will work just fine.
The choke is .62 mH.
I do not think the values are too critical.
Posted: Fri Dec 30, 2005 5:47 pm
by tkiuntke
Thanks again Will. I really appreciate the help.
Toby
KC0FRU