Thank you skipp.
Money is not an issue really.
the repeater belongs to our club. Its in between homes now.
You are correct about the LPA. I was looking at the schematic for
that - figured I could maybe swap out the transistor for an MRF (or
similar) that might do 2 in, 25 out and avoid the spurs.
I did knock the 7 watts down to a watt or so - could be thats still
too much power in.
I'm going to put it back to normal and leave it alone for now.
Ian
At 03:32 PM 4/22/2009, you wrote:
> va...@... wrote:
> I inserted a small 20 watt PA after the TX port on our
> Hamtronics REP-200 UHF machine.
Who makes the PA? 20 watts... It probably has a nominal drive
value of less than 7 watts for sure... The original bare
Hamtronics exciter (transmitter) is probably rated for 1.5
to maybe 2.5 watts output. Normally the repeater has an LPA
(amplifier) stage inside the box and it's output is somewhere
in the 12 to 25 watt range (for the basic model depending on
the version).
> Repeater puts out 7 watts into my Termaline after all the
> filtering etc.
What is "the filtering"? a duplexer?
> With the amp, output is 15 watts, 3DB gain, however the
> signal on the air seems weaker.
You are probably over driving the extra/external amplifier. Not
good...
> Its not a desense issue - I can still trip it from a fair
> distance - just that the transmitted signal is less with
> the amp - go figure.
If you looked a spectral display of the output... an over driven
amplifier would not be hard to figure... you'd probably see the
buckshot. If you're receiver doesn't seem to suffer, you're
probably getting lucky.
> The repeater is now at my house temporarily, so conditions
> are not ideal for height etc.
For you, the repeater or the antenna? :-)
> Any ideas?
Marry someone with a lot of money...
Seriously, give us more information about what each item is
and it's power level. We'll give you some ides. Chances are
you're probably over driving an external amplifier. If you'd
like to use the amp... there are ways to reduce the drive
level without grief.
> Also, if anyone has a nice 75-100 watt UHF PA around, for a
> reasonable price....well you know the rest.
You would experience serious trouble placing that size amplifier
on your stock repeater without mucho extra protection in/on both
the receiver and transmitter side (not to mention the duplexer).
> Cheerio
> Ian
> VA2IR
Raisin Brand...
:-)
s.
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