Perils of hilltop tower visits: deer hunters, failing brakes and pirates

There is a tower on top of a hill, where due to the combined hill relief and tower height flight paths were permanently altered, according to possibly apocryphal lore when the tower was built by Motorola. I rode along on a 15% grade road to see the repeater site. Due to the location there was a fair amount of stuff up here–rim shot to several medium-large cities. 50-60 miles range was not a challenge with this system.

One of the EF Johnson CR-1000 100 Watt repeater PAs had no transmit. We found a bad PA transistor, which didn’t happen that often unless the power amplifier was mistuned or bad SWR or tried to transmit with too high power due to poor measurement technique. We checked all the hardline and duplexer connections, and all was well. We put a Kenwood TKR-820 25 Watt in its place–this usually will cause residual complaints from those on the edge of the coverage area, but better than no transmit.

Commercial two-way radio repeater piracy

Sidenote: because they didn’t track airtime usage, and because the tone panel for the CR-1000 repeaters simply repeated out the tone frequency that came in, this meant one could play some special tricks with PL tones. In particular, if 136.5 Hz was one of the authorized user PL tones, then any DPL looked enough like 136.5 Hz due to the 134 bps rate that the repeater would transmit! The 136.5 Hz user wouldn’t be bothered because the repeater just tried to transmit DPL, not 136.5 Hz PL.

Caveat: the repeater transmitter was not capable of DPL transmit properly, so most mobile radios could not decode the highly distorted DPL. This meant the other UHF commercial repeater pirate would have to use carrier squelch CSQ receive.

Another thing you could do was transmit with a PL far off the authorized tone, so that you wouldn’t trip the authorized user’s receivers. You needed a radio with continuously variable PL (like old EF Johnson radios!) or use one of the “in-between” PL codes.

The safest practice was deemed to be DPL with CSQ receive, since you never knew how broad some old farmer’s 1970s EFJ mobile was for receiving off-frequency tone PL.

No brakes down 15 % grade!

On the way down the 10-15 % grade from the tower site, we discovered that the rear rotors were completely seized open. And the front brakes were worn with a weak brake cylinder. This meant we had to downshift and let the engine scream and hope there wasn’t an overrev that would kick it into neutral. This was less than a dirt track, it was slippery unmown grass with dampness from any frost the night before.

We got off track and back on track, but a lot of stuff got bounced around the truck. We stopped to let off the adrenaline and take nature’s call. As we were just about to go, a couple hunters came by and noted we were really wearing the wrong color for this time of year to be stomping around in the woods! I had on my heavy tan Carhartt jacket, good for all day outside in frigid weather with a flannel underneath. Good thing our engine made so much noise I suppose, so crashing through the branches a minute later in tan didn’t give the wrong impression!

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