Hello W3ML,
I've been following this thread over the weekend and I think the issue
has been addressed. I would check the antenna and related connectors.
In fact, for my 2 cents, I'd replace the G7 with a commercial grade
antenna, such as a DB product or equal. Now, to your scenario today, I
would ask what the wind was like? If memory serves me correctly, that
G7 has a couple of joints and is somewhat flimsy in terms of material
strength and antenna height.
There ya go,
thp
W3ML wrote:
Hi Tom,
I did crank up the power to 55 watts out of radio and that gives me 45
out of the duplexer. Decided on this wattage until I can figure the
problem better. It is working better than before, but still having
trouble.
So from what you said about power coming out duplexer, the duplexer
must still be okay.
However, during the day today there were 3 hams talking and they said
(later) that all of them were loud and clear. But, when I got home and
tried to call one of them, he was covered in noise.
Later one of the others called in and he would be clear, then the
repeater would cut out and his signal would be gone, then it would
come back with noise on his signal and then clear again.
Then the other one came in with a lot of noise, then he would come in
with a little noise and then no noise at all and then back again
through this cycle.
This cycle of noise and then no noise is driving me crazy.
The set up is this:
GE Mastr II VHF mobile running into a 6 cavity duplexer set to our
freqs with a service monitor prior to bringing it here.
There is a bandpass filter on the receive side after the duplexer and
before the radio.
We have used 1/2 inch hardline going up to the used G7-144.
Then only thing I can think of is the radio is bad, the antenna is no
good and the coax is shot.
Now, the radio was given to us by a group that had used it, but
decided to replace it with a Kenwood.
I am thinking that they had the same problem and that is why they gave
it away.
Any advice would be greatly appreciated.
73
John, W3ML
- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com>, W9SRV <tgundo2...@...> wrote:
>
> Ok-
>
> 1. Where are you checking the swr at in the chain? Make sure you
bypass the duplexers to check the antenna, the cans can throw off the
reading on some meters like you describe using. If you are less than
1.5:1 I would not worry too much more about it, any reflected power
will get eaten up back in the cans. If you are really concerned about
protecting the TX put a circulator in-line with it.
>
> 2. Make sure all the interconnecting cables are good shielded and
not foil/ braid type. RG-213 and RG-400 are good choices, though there
are a few more.
>
> 3. Terminate into a good dummy load. Set you output power to 80-90W.
Then run thru the duplexer and check the power coming out of the cans.
You should see something like 60-70w, depending on the spec of the
duplexer. If your seeing much less than you may have a duplexer tuning
issue.
>
> Figure out the real problem, let the radio run at a real spec power
output, than absorb the title of "far lord" as every one thanks you
for giving the repeater twice as many s-units. (then be prepared for
the next round of complaints that become your problem)
>
> Tom
> W9SRV
>
> Sent from my iPhone
>
> On Oct 4, 2009, at 5:46 PM, "W3ML" <w...@...> wrote:
>
> No, except when it was at the 2o watts the swr was almost 1 and
someone said that was the problem causing the de-sense. So we were
afraid to run it higher.
>
> Like you said guess it was only a problem from running too little of
power.
>
>
> Thanks and 73
> John
>
>
> --- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com>, W9SRV <tgundo2003@> wrote:
>
> You answered your own question :
>
> "So it appears that this radio, which is a GE Mastr II mobile,
doesn't like to run at the lower wattage of 10 to 20 watts out."
>
> 110w radio will not be stable at 10-20w. If you look at your output
on a spectrum you probably have spurs all over the place. Any reason
you cannot run it at least 1/2-2/3 power?
>
> Tom
> W9SRV
>
> Sent from my iPhone
>
> On Oct 4, 2009, at 4:46 PM, "W3ML" <w3ml@> wrote:
>
> So it appears that this radio, which is a GE Mastr II mobile,
doesn't like to run at the lower wattage of 10 to 20 watts out.
>
>
>
>
>
> ------------------------------------
>
>
>
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