RE: [Repeater-Builder] R1225 repeater

Mark, You should order a copy of the R1225 service manual 6880905Z53 from Motorola Parts while it is still in print. It costs about $13, less than 1/3 the cost to make a color copy of it. The receiver front end has back-to-back diodes to provide some protection against high voltages, but a

RE: [Repeater-Builder] R1225 repeater

Thanks Eric. I was kinda hoping that someone had the manual and I could get just the RX board layout and parts list pages... Even at $13, I'd rather not spend the money for a one-time use - but it looks as if that's the way I'm going to have to go. Thanks and Happy New Year, Mark - N9WYS

RE: RE: [Repeater-Builder] R1225 Repeater

I'll give this a try, Ron. Thanks! Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of Ron Wright Mark, Some verification of the duplexer tuning can be done with 2 HTs, one with an S meter. Simply use one HT on low power, 0.1 W, transmit thru the

Re: [Repeater-Builder] R1225 Repeater

What I have done to Rough it in is use a low power watt meter (mine is 4 watts) and a HT or mobile rig. You can at least see if you are way out before you connect an HT to receive. Brian ka9pmm n9wys wrote: I'll give this a try, Ron. Thanks! Mark - N9WYS -Original Message- From:

RE: [Repeater-Builder] R1225 Repeater

Good idea, Ryan! Thanks! FWIW - this has been shelved for the time being, due to the severe winter WX (i.e. ice storm) in the area.. Once the weather is better, I'll get back to work on it. But for now, I need to devote time to my volunteer efforts with the county EMA. Thanks all! Mark

RE: [Repeater-Builder] R1225 Repeater

As far as having the coaxes switched, we marked the cables before disassembling the duplexer for re-tuning. However, I do wonder if the guy tuned the notch to the same freq on both sides. I don't recall seeing him change the freq on the monitor while he was tuning the duplexers last night.

Re: [Repeater-Builder] R1225 Repeater

Have you taken the duplexer out of the equation, put a dummy load on the TX port, a tuned antenna on the receive port and see if the receiver is receiving properly? If you have a service monitor, check to see if it is within performance specs for 12db sinad and 20 db quieting. If it is, then

Re: [Repeater-Builder] R1225 Repeater

Well let us know how it turns out. Hopefully you didn't make the easy mistake of having the coaxes off of the RX and the TX connected to the incorrect ports on the duplexer??? OR maybe the fellow whom tuned the duplexer transposed the high and low sides??? easily enough done and a very easy

RE: [Repeater-Builder] R1225 Repeater

I just brought the repeater back to my shack this afternoon. the service monitor test will be one of the first performed. Although I did not tune the duplexers personally, I trust the guy who did tune them - and he did two of them for us. So if it is a bad duplexer, it's actually TWO of them.

RE: [Repeater-Builder] R1225 Repeater

Mark, Are we talking about the R1225 transceiver itself, or is the repeater actually a GR1225, RKR1225, or a GR400 or GR500 X-Pand repeater? If one of the latter, the duplexer is usually a mobile notch duplexer with six helical resonators in a one-inch-thick package. Does your R1225 repeater

RE: [Repeater-Builder] R1225 Repeater

Hi Eric. The machine I have is as you described as the latter - it employs a mobile-type, 6-resonator notch duplexer. It is on 452/457 MHz. As for the exact model designation, it says Radius GR1225 on the front panel... We've tried reversing the cables going to the duplexer, with no change in

RE: [Repeater-Builder] R1225 Repeater

, November 29, 2007 9:55 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] R1225 Repeater Hi Eric. The machine I have is as you described as the latter - it employs a mobile-type, 6-resonator notch duplexer. It is on 452/457 MHz. As for the exact model designation, it says Radius

Re: [Repeater-Builder] R1225 Repeater Exciter Output??????

I believe these repeaters are based on the MaxTrac/Radius/M1225 product line; as such they probably output 25 or 45 watts. You would need to use the radio service software to turn the output power down, however it will be unstable and quite inefficient at such a low level. The power won't remain

Re: [Repeater-Builder] R1225 Repeater Exciter Output

It depends upon which one of the four models of the R1225 you have. Here they are: M03GRC90C2AA, 146-174 MHz, adjustable 1 to 10 watts M43GRC90C2AA, 146-174 MHz, adjustable 25 to 50 watts M04GRC90C2AA, 444-474 MHz, adjustable 1 to 10 watts M44GRC90C2AA, 444-474 MHz, adjustable 25-45 watts The