Around 1 August (about two weeks ago) as a thunderstorm

passed over Rolla, many of us noticed that the 147.210 MHz

repeater no longer performed normally. Subsequent to that,

we removed and tested the preamp in the repeater cabinet

and testing by Peter (WB9KHR) showed that the preamp was

damaged. However, even with the preamp removed, some

users noticed repeater did not seem to transmit as strong a

signal as before.


Jeff (KD0JLM) who works at the PCRMC/Medical Office Bldg.

was able to inspect the antenna and he saw that it was

physically damaged. So, we arranged to replace it this

morning, and these pictures show what we found.


Thanks to Peter (WB9KHR) for "loaning" us his two-element

vertical, yielding 6dB gain (as opposed to the damaged

GP9N which offered 8.5 dB gain). After replacement, we

found that the resonator cans were grossly out of tune, so

did a quick tune to return the repeater to near-normal



We yet need to replace the preamp, do a full and proper

tune on the resonator cans, and observe how well the

repeater operates with the replacement antenna. Depending

on the results, we may either keep the replacement in service

or replace it with a new antenna.


Some work also needs to be done on the remote-base link

to 146.790 MHz to improve the received signal at the MOB



Photos & report by Joe, K0OG, except the three photos by

Steve, N6RHQ, as noted.


Thanks to Jeff (KD0JLM), Steve (N6RHQ), and of course

Peter (WB9KHR) for their help today.

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