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Yea, i have as well.. Water and moisture surelty contribute to the corrosion factor. About 10 years ago i restored a 1970 Yamaha 250 Enduro Motorcycle. It sat in my dads back yard for over 30 years. Many of the steel bolt used for the aluminum casing were seized with some destroying the threaded casing. The bolts that were steel to steel cam out with ease.

Once upon a time aluminum was used for house wiring but there were fires in some places. It’s a little trickier to work with aluminum because aluminum oxidizes very quickly and aluminum oxide is a pretty good insulator. We still use aluminum for utility conductors but with quite a bit of extra training to do it right when joining copper and aluminum. Gil @WRUU653 would be much more likely to understand the process than me. But that’s at DC and and 60 hz. RF travels through molecular thin oxide layers pretty well and I agree with you that stainless steel and aluminum don’t appear to bother Comet.

Wouxun in the title...seems to be a trigger for him, was guaranteed a negative response from him.

Depends on the coverage area of both repeaters. If they overlap, you will have interference when both are transmitting at the same time. Having different squelch tones is not the same thing as having different frequencies. My suggestion - Set the second repeater at a different frequency to avoid potential problems.

If the tones are the same, both repeaters would come up and 'repeat' your transmission at the same time. No loop could be created. If you set it to different tones, then the only issue to watch for is mistakenly causing interference. The users of each repeater would probably need to just transmitting a tone, but not using tone squelch. This way they can tell if the frequency is in use. Either that or they would need to 'monitor before transmit' if they have a monitor button on their radio.

So tone is TX. And tone Squelch is TX and RX?

Won't anyone listening on that frequency with no tone set, hear ?

Can two repeaters with same input and output frequencies but with different transmit and receive tones for each repeater work without creating a feedback loop or some other problem? Our situation is we have two repeaters, one is in operation now. It does not cover a critical location in a mountainous area. We have a second repeater set-up that is identical in frequency and tones. If the second repeater's tones were changed to be different from the first repeater could they operate in close proximity (10 miles) with out creating a problem? Anyone out there with similar experience?

Stop being such a looser. I doubt you even read it.

I have a Bridgecom GMRS repeater that uses the Maxon radios. The transmitting unit died. Can I just swap it with another Maxon unit or would I need special equipment to sync whatever? Bridgecom says they will not service their repeater if the transmitting Maxon unit is at fault.

The fan appears to be a rather standard-sized commodity PCM fan. You could probably replace or upgrade it with one from Amazon. With the TDR function on the 'C' key you can pretty quickly switch off the second band, but you're right, automatic muting as an option would be nice.

As I said, I've seen houses wired with aluminum wire and secured with steel screws without any significant corrosion. Granted, they aren't exposed to the weather, but they carry a lot of current. I'm not saying it doesn't happen and I'm not going to start randomly screwing dissimilar bits of metal together, but if Comet uses stainless steel radials screwed into an aluminum base, they must not be too concerned.

Cars and motorcycles do use dissimilar metals for fasteners and they also advise use of anti-seize. Also, dissimilar metals for fastening use does not promote the corrasion effect as much as it does when electrical current flows through the dissimilar metal.

I posted your quotes..

I've had this radio for about 2 years and it's a rock solid performer. Lots of compliments on how I sound from it. Functions very well, puts out full advertised wattage. Easily unlocked for full TX range to match the RX range (murs,marine vhf, gmrs,CB and more) on it using chirp. I've had zero issues with this radio and it gets used quite a bit. Yeah the 10m band is kinda useless without sideband unless your doing CB on it. Very nice radio and for what it does, it's pretty cheap compared to the mainstream HAM mobiles. My only complaint with it is the fan tends to make noise in cold weather. So you get in your truck and it's 10 degrees, the fan makes a bunch of racquet until the vehicle or radio warms up. The KG-1000G's do the same thing. The fan needs a redesign or different bearings or something. But it's never prevented it from working. The noise is short lived. That and I wish there was a setting like the 935H added over the UV8H to mute the secondary area while TX'ing on the main area.

Tsql is for a repeater that uses the same tones in and out

Right, and that's what I did. It was a little harder than I would have preferred because the masthead doesn't provide its own good ground plane, the forestay, backstay, and upper shrouds can actually influence the apparent ground plane in weird ways, too. A mobile antenna such as the Comet CA2X4SR would have been broad-band enough, but not compatible with the wonky ground plane 30 feet up the mast. I ended up with a base-station broad band dual-band antenna that provided acceptable SWR from 2m through GMRS, including Marine VHF. I don't remember the model I went with, but at this point it works nicely. I prefer keeping a dedicated Marine VHF radio, as they offer marine-specific features not found in amateur radios. So that rig will always be a Marine VHF / GMRS dual radio setup.

If you can find a single antenna that covers Marine VHF and GMRS then you would only need a single diplexer. It would be no different than how we have our 2m and 70cm repeaters setup.

Right, I've done one version of this on a sailboat; At first I considered putting one diplexer at the top of the mast, and one at the base, to allow a single LMR400 run up the mast to drive a dedicated marine VHF antenna, and a dedicated GMRS antenna. And then the one at the bottom to feed a dedicated Marine VHF radio, and dedicated GMRS radio. But then I ended up going with a broad band dual-band antenna at the top, eliminating the need for the top diplexer (and its associated signal loss), while still allowing two radios at the bottom. Inside a sailboat mast, space for coax is rather limited, and the weight of running two separate coax lines is also not desirable.

Diplexers work when using a single antenna with a radio with dual antenna connectors. The Icom IC-9700 is just on example. It has two coax connectors, one for VHF and one for UHF. Most guys will run a single dual band antenna to the radio using a diplexer. Or as Steve was asking, one can use a diplexer to connect two antennas to a single coax connector on the radio. We actually use dual band repeater antennas for our 2m and 70cm repeaters and a single hardline into the building. Then it goes through a diplexer to the two repeaters. That setup has been working great for years now.

Yeah, for that you'd either need one of those crazy looking antennas that supports quad bands (they often have a short vertical half-way up the main vertical, standing off about an inch), or a diplexer. I see the Diamond MX62M that has a 1.6MHz-56MHz branch, and a 76MHz-470MHz branch. That would be almost perfect. Then for antennas you would need a 2m/70cm, and a 10m/6m.

I wasn’t thinking about cross banding as much as having a dedicated antenna connection for the 10 meter antenna.

Good info. Thanks. I may have to give it a try next time I'm in less congested RF-space.

You do not need a diplexer or dual antennas on radios that have only one antenna connection and have cross band repeat functions. I use cross band repeat quite often on dual band radios. Just set Side A to the 2M frequency, usually a repeater, and then set Side B to a 70cm frequency that you want to use on your HT. Then go into the radio's menu and turn cross band repeat on.

Exactly this ^^^ The info was always there, it was just the reference to pages was incorrect in quite a few places if not all. I would just use a search on key words in the PDF to find relevant info to what I was looking for. I keep a PDF of all my manuals to reference and just replaced this one with the updated version. Shoutout to @dosw for passing along info of updated version.