This is the official webpage for the KA1ZGC 147.345 repeater in Skowhegan, Maine.
The repeater is located at the top of Bigelow Hill (affectionately known as Henryellar Mountain in certain circles) in Skowhegan, Maine. The site is shared with many RF services, most notably the site owner, WA1HLR, and WHQO-FM on 107.9. W1LO has also recently put up a repeater on 446.325 with a PL of 203.5. The antennae for the repeater are mounted on a 90-foot tower, with the transmitter antenna at 24 feet and the receiver antenna at 70 feet.
The transmit antenna is a 2-bay folded dipole fed by 30 feet of 7/8-inch Heliax, the receive antenna is a Diamond X-5 fed by 81 feet of 3/4-inch Heliax. The X-5 is shared with the 440 machine, which uses it for both receiving and transmitting.
This is a shot of the repeater cabinet during initial installation and testing. It looks very different from this today.
Adding to the antenna isolation are three 4-inch cavities on the transmit leg, and three 3-inch cavities on the receive leg. These are nowhere near the quality of a set of Wacom or TX/RX cavities, but still provide an added 70dB isolation at the cost of a 1.5dB insertion loss.
The repeater itself is a GE Mastr Pro Deskmate station with an NHRC-5 controller. The transmitter strip is the good ol' fashioned 80-watt hybrid strip with a 5894 final. Most of the real GE nuts swear by these, citing cleaner RF out and a more stable power supply than the solid-state Mastr Pro transmitters.
None of the features of the controller are being published at this time. I want to get a sense of the usage demograph before I start enabling toys.
Stop yelling, I can hear you now... - Aug. 1, 2004
Much work has gone into the repeater over the course of the last couple of months. For starters, the waterlogged 1/2" receive feedline has been replaced with 7/8" heliax. When this was done, we also took the opportunity to raise the receive antenna all the way to the top of the tower. This puts the receive antenna at 90 feet.
Warren, W1LO, owner of the co-located 446.325 repeater, dropped in a few weeks ago with a service monitor. We squeezed every last drop we could out both repeaters, and determined that the 2M receiver's sensitivity was about 12dB or so shy of where it really needed to be. This isn't all that unusual with GE Mastr Pro receivers, but was still a bit of a bummer.
To make up for this particular deficiency, I have installed a JFET preamp with roughly 15dB of gain. Using a GaAsFET preamp at this site would be an excercise in poverty, given the intense RF at the site, and occaisional nearby lightning strikes.
I am pleased to say the usability of this repeater has gone up exponentially, and more improvements are slated to take place this year.
Stay tuned.
Now you hear it, now you don't - Dec. 19, 2003
This is what makes repeaters so much fun.
For a while now, usually after service visits, the repeater transmitter would sometimes cut out. This has been a real mystery to us up until now.
I am pleased to report that Tim found the problem. It turns out that the crystal was loose in it's socket. Now and then (after a little vibration, like me opening and closing the cabinet), the crystal was losing it's connection. A few minutes with some hand tools fixed the problem.
Things that go screech in the night - Dec. 2, 2003
You know that irritating screech the repeater would sometimes make (you know, the one that sounds like a lightsaber duel)? Ever looked really close at the tower shot? Look on the left hand side of the tower, next to the two-bay folded dipole. See that thing that looks like a rusty spring hanging from a piece of rusty steel wire? That's a rusty spring hanging from a piece of rusty steel wire.
I always knew it was there, and I always knew I should take it down, but when I dropped by the site last Saturday I caught it in the act of flapping in the strong wind in time with the noise bursts. So I threw on my belt, hauled my sorry butt up the tower and yanked it down.
Only a total fool would climb a tower on a day with 20+ mph gusts, you might say (and you'd be right), and with God as my witness, I am that fool.
Head swap-and-reverse - Nov. 17, 2003
I was (am) getting tired of the waterlogged feedline, so last Saturday became impromptu First Time the repeater was run full-duplex into one antenna. Unfortunately, that antenna was the transmit antenna. The performance was absolutely fabulous, as long as you were between Skowhegan and Bangor. Areas towards southern Maine lost signal into the machine, which forced me to put it back to dual-antenna configuration, in spite of the compromised feedline.
The current receive feedline will be replaced soon. This will at least equalize the receive and transmit coverage. For the moment, it's no better or worse than it was before the experiment.
Plumber at work - Nov. 10, 2003
After some downtime this weekend, the cables for the duplexer harness were all replaced with 1/4-inch Heliax. This means the repeater now has solid copper shielding from the radios (closeup of the Rx strip connector) all the way to the antennae. No immediate difference will be noticed since the receive feedline coming down the tower is impregnated with water. This was primarily done in the name of noise reduction, as the previous duplexer harness was not very well shielded.
Drip, drip, drip... - Nov. 3, 2003
It has been determined by scientific means that there is water in the feedline that is feeding the repeater's receiver. This is why a number of you are unable to access the repeater when it's full-scale coming back at you. We hope to replace this feedline before the snow flies. Stay tuned here for details.
KER-BLAM!! - Oct. 8, 2003
On Friday, Oct. 3, 2003, Bigelow Hill was struck by lightning, big time. CMP sustained heavy damage, and Tim's wire array and telephone line were both rendered unusable.
The blast to the wire array also caused a flashover in it's phase-reverse relay, which is powered by rectified 120V AC on the same 20A circuit the repeater is on. The flashover in the relay caused that fuse to blow, which took the repeater off the air.
Since most of us were at Hosstraders when this happened, the repeater stayed down until Sunday morning when I returned to the site and replaced the fuse.
The one piece of good news out of all of this is that the repeater was otherwise unharmed. Others weren't so lucky.
Sorry for any inconvenience caused by the outage.
| Name | Callsign | Affiliation | Thom Rounds | KA1ZGC | Repeater Owner | Tim Smith | WA1HLR | Site Owner, Primary Control Operator | Al Chouinard | KA1ZZC | Control Operator | Chuck Sullivan | WA1IIE | Control Operator |
Special thanks to Warren, W1LO, for taking some time with a service monitor and doing the repeater some serious favors.
Every time I unkey, someone whispers "strap". Who keeps doing that?
Me. That's the courtesy tone.
Okay, so why is that the courtesy tone?
It's a strapping repeater.
Is this an open repeater?
Wide open. I lost the back cover to the cabinet ages ago.
Is this repeater affiliated with a club?
No.
Who is paying to keep this repeater on the air?
Me. I refuse to let this repeater become anyone else's financial burden.
However, what I haven't paid for myself has been borrowed from Tim,
and no small amount of his time and effort went into this, as well as his site and his tower.
Can I contribute in any way?
Free beer is always nice, as are attractive females.
Handing me a hot italian sausage smothered with peppers and onions (ketchup, mustard, and relish) at a
hamfest is also a good way to get on my good side. Other than that, we're all set, but thanks for asking.
