Batboard

Guys...

Im in north central Kansas...kinda the boonies, and there is no 900mhz here...but I want to change that...Im looking for your opinions and advice...

I have access to a 200' tower that is about 3600' elevation...We have a vhf paging system on the tower, a 2m repeater, 6m repeater, and soon to be a 70cm repeater.

I am wanting to construct a 33cm repeater to put up...the closest 33cm listed is in Topeka, about 4hrs away.

I was going to build repeater out of two maxtracs or spectras...I have found a duplexer, and a 350wt linear amp, I have the power supplies and cabinents for the repeater.

I am looking for advice on this contruction, a rough estimate of coverage, and advice on base antennas. I was thinking about a group of 5 yagi's i found on ebay and putting them around the around the tower...or anything that someone would advise..there is 7/8" hardline run up to about 185 feet that I can use for a feed line to that point.

Im new to the 900 scene, so anyhelp you can give would be great!

Thanks
Tim
kdoezq
victoria, kansas

A group of 5 yagis? WTF? If you're looking for omnidirectional coverage, why wouldn't you use an omni antenna? Assuming you've swept the existing hardline, it should be sufficient for 185'. I'd look at a DB809 or similar for an antenna.

Coverage is highly variable - best bet is to learn to use Radio Mobile and do some coverage plots for your specific site.

I'd also suggest a real repeater, like the MSFs, Quantars, etc. discussed herein, rather than two mobiles strapped together.

350 watt linear? I'd make sure your duplexer will handle that sort of power, or you'll destroy it in short order. You don't really need that sort of power unless you have a special application, like 900 paging.

6 meter repeater... neat... I will try to track down the freq.

BTW, I'm just south of Lawrence.


EDIT: hey man, didn't realize it was you... ha...

Just remembered the PM over at HS after reading this.... check the inbox over there.

Mendolson's in Ohio (and ebay) had some 10 dbd celwave repeater grade antennas for sale for $169 plus shipping. We have a few of them up on 900 around here and they work very, VERY well. They have them in two splits (890-915, 915-940). We bought a few of both splits, but there is really no difference between them. You can use either split.

John

Havent made any decisions on the antennas, the yagi's just caught my eye....and I had not found any omni antennas at ebay...ill keep looking...

900mhz in western Kansas is does not exist...no outlet out here for a 900mhz repeater, and I was wanting to try with the spectra/maxtracs to see how we go. I have been looking at some used repeaters but shipping from back east is a dog!

I will go check Radio Mobile to see what we get!

Like I said, Im looking for insight and opinons...this is a new trail for me!

Here are the item numbers on ebay for the two antennas I'm talking about. They were made by Celwave for a Motorola contract and are exceptional antennas.

390018209457
360117397708

Check them out.

John
N1OTY

If the Stationmasters are too big/expensive/whatever for you be advised that Comet and
Diamond make a nice 900 mHz fiberglass vertical that's only about eight feet long (ships UPS) that has
gain similar to the commercial units. I've had one of these up and working for about two
years with no problems. The ham antennas are also built to definitely work properly in the
927/928 mHz area for repeater output and simplex operations.

Hey John, How were the shipping charges ?
They look like a nice deal.
Thanks
Bob P W2YMM

n1oty wrote:Here are the item numbers on ebay for the two antennas I'm talking about. They were made by Celwave for a Motorola contract and are exceptional antennas.

390018209457
360117397708

Check them out.

John
N1OTY

Well, we got them before Mendolson's raised the price. We initially bought 10 of these antennas for $50 per antenna. The truck freight for 10 antennas shipped to a COMMERCIAL address (cheaper that way) came to $190 (about $20 per antenna in bulk). We got an even amount from each split. Our testing indicated that there is virtually no difference between the two splits and both versions are completely useable throughout the entire range of 902-928. We subsequently bought another 12 antennas at $50 each plus shipping.

Even though Mendelson's has raised the price to $170 plus shipping, this is still a bargain. These antennas retail for over $1000 plus shipping at Tessco. We had been using Comet KP-20's for our repeaters prior to acquiring these puppies. Once we replaced our KP-20's with these antennas our repeater footprints nearly doubled. I cannot speak highly enough about these antennas. These antennas are true commercial duty. They are built much more ruggedly than KP-20's.

John
N1OTY