OK, more questions for the collective. (Yes, I know - doesn't he ever
quit?? hehehe)
I'm about to delve into converting one of the 150W Motorola STF2520A power
amplifiers for my 900 MHz repeater. I read on the VHFSouth web page, where
the conversion/modification procedures are listed, references to voltage and
a yellow wire inside which was called the "enable" wire.
So here are my questions:
1) Does this PA require a main power source of 24VDC or 12VDC? I'm
thinking 24 - 28VDC, and I want to make sure that I don't let the magic
smoke out, but the verbiage there was a bit confusing. ("The power wires
are pretty easy to pick out, but note that the "enable" line is the yellow
wire. It calls for +15 volts, but we are told that +13.6V will do the job.")
Does the reference to "it" mean the enable wire only??
2) Regarding this "enable" wire - is the enable function contained
within the Control Board of the PA, i.e. RF sense, or should it need to be
fed with an independent source?
3) And one last question about the enable wire - IF it needs to be fed
with an independent source, should I "relay" it (such as tied to COR) so the
PA is only enabled when TX is present, or does that really matter? (Can it
run 24/7/365?)
I plan on mounting the PA board(s) themselves on the main heat sink in the
Glenayre station cabinet I have. (I've stripped out all the Glenayre PA
components.) It is supplied with a HUGE cooling fan, so I am not overly
worried about heat issues with the PA once installed.
Unfortunately, nobody has answered any inquiries I posted directly to VHF
South, or to AA9IL. This is the final phase of construction, so
understandably I'm anxious to finish this project and get it on-the-air. If
anyone can assist me - either on list of off - please do so!
Thanks in advance!
Mark - N9WYS
For direct replies: n9wys <at> ameritech <dot> net
