zap

On a bit of a funny note. Last time we went to Ski Apache, we thought about mounting a DB-408 in the back of the truck while we were skiing for our portable repeater.

Either the 409 Radio shop or the Radio shop 888 for the duplexer. Heat is a concern but after spending a year taking various classes covering the subject of thermodynamics, you figure out ways to move heat without unsealing your watertight ammo can. I think I calculated a battery life of roughly 23 hours at a 15% duty cycle but how that actually plays out... Who knows. Also looked at adding a 10 or 20 watt amp but for the first one I think I'm going to keep it simple.

So I had this interesting idea while looking at some "Tactical" repeaters owned by the Texas Department of Transportation. Basically they are VHF boxes with Li-on battery packs about the size of your average Pelican handgun case, a 5W full duplex board and a notchplexer. Then I started running some power draw numbers with the Maxon data radios…then the Ritron data radios, and then Tecnet released a new line of smaller data radios along side their Maxon line at IWCE this year. Then 11 Motorola RNet 450's plopped in my lap from a SK's estate. Crystal controlled, single channel data radios that'll run 4W out (on what is probably a 10% duty cycle) with some other junk in the case that isn't actually needed for "repeater" duty. So I've though about throwing a repeater (or two) together in an ammo can, adding a small duplexer (the 20W rated Jensen duplexer will fit nicely in a 30 cal can), adding some external heat sinking and a battery and seeing how it runs. Just gotta track down the service manual for the radios if I'm going to use the RNet radios… Any thoughts?

So it's 1050 Hz paging…a GM300 should be able to handle it just fine. You really only have to use something like a NHRC 3.1 or a similar setup that will allow the crossing of systems together. Many alerts also send a 1050 Hz post tone these days… You could also use a controller that has a 30 - 45 second TOT on the "WX input" side that could be easily wired to reset the radio in the instance. I've toyed with adding WX alert to a local GMRS repeater or two. Would certainly be interesting.

Nearly all of the current Kenwood analog mobiles are type accepted for GMRS…but I'm not too in-depth on the features or how easy to acquire the programming software is. Motorola's are fairly cheap…if you buy from the used market (there is honestly a good like-new used market out there). One of my current favorites is the Motorola PM400 (a CM300 is the same radio without LTR trunking). The reason being, it's still under support (though recently out of production), programs in Windows. The other big reason, you can get someone to dump a GMRS cqodeplug into it and enable the programmable buttons for the following: PL Defeat/Monitor, a menu setting where PLs can be edited (take note there is a little more functionality in this compared to MPL) on a per channel basis and scan list can be adjusted, scan/nuisance delete, and tx power/talk around. Most of my experience is in Motorola so it's what I can really recommend. I have some Icom's and Kenwoods but in my experience editing the PL's isn't as easy (usually have to enter a FPP mode which first has to be enabled in the software). Just my 2¢.

This is my "stash". http://i1245.photobucket.com/albums/gg586/zap_uh_lack/Mobile%20Uploads/E9EB3837-8ED9-461A-B6F9-3A8DD353178B_zpstjuyvi2s.jpg

You can build a decent quality repeater (better than that) for around $300 using surplus mobiles. Sent from my iPhone using Tapatalk

Well, it's only 5W…and you can't edit the frequency list. Wonder what it would cost though.

The 888 is rated a (per the sticker) at <4W. Which means less than 4 watts. I ended up throwing one on my General Dynamics R8000 and it cam back as 1.96W in the GMRS area so the sticker did not lie…it was less than 4 watts.

it's essentially a DOS emulator.

Best way to run audio is on line or flat levels. Sent from my iPhone using Tapatalk

Well, seems that works well. I've never tired it in virtual box. One question I have to ask, which version of the 1225 RSS are you running. 3.1 Isn't designed for XP but will run on 32 bit 7 and 4 was specifically designed for XP and I've yet to have a problem with it on XP. DOSBox works well for all things Kenwood...starts having issues when you try and work it on Motorola and Icom software (but there is plenty of evidence that it will work).

R100's are complete repeaters. They made a 10W version and a 25W version (I have one of each, well technically one is a MCR100, both DPL) but they are just a TX only Radius and a RX only Radius in a box with better power control. I actually pulled a 75W PA off a old Mocom-70 (only thing worth really salvaging on that radio) to eventually drive with a GM300 someone stripped the PA guts out of ore maybe even a Micor exciter. Lot's of amateur stories of guys pulling Micor PA's and driving them with GM300's.

I've always had good luck programming older radios with a P3 Toughbook using FreeDOS or a P3 Dell using 98SE. Never have tried older software on the Dell but I've gotten some of the older Motorola stuff to run by disabling the cache using the cacheoff.com program that can be downloaded from Repeater Builder. It's the generic equivalent to MoSlo.

I've got a VHF channel master laying around somewhere…only down side to them is that the VHF ones are 20ft long and a single piece. I've got a 6dB Telewave antenna that was being used temporarily and worked well. For a building installation/tower install I try and use nothing less than a DB408…usually end up using 420's though.

So far optimas are the only batteries I've found worth a flip. I had a Yellow top make it 8 years in my XJ. Then it got to the point where if it wasn't on a maintainer during times the temperature dropped below 45º F. I've been testing out the slightly cheaper Duralast AGM's in both my XJ and Trailblazer. So far so good.

Only place I've found the real version 4 is on the p25.ca forums under legacy radios. They were referring to the P1225 but the RSS covers the whole 1225 family.

There's an RSS version made for DOS, one made for 95, one for 98 and one for XP. RSS 3.1 is the commonly available one and was written for 98 but it should run just fine on a 7 computer (I never had an issue with it at least). RSS 4 is the harder to track down version that was written specifically for XP. CPS 6.04 is the commonly available CPS for the Profesional series radios (HT750/1250, etc).

Wouldn't be bad to get the name of the guy you talked to as well anytime you get info from an FCC office…cover you bases in case you ever need them.

Generally a red blinky light means channel busy (RX). If an amber light is on, generally means busy channel (different PL or microphone is off the hook).

Show me where it states that.

Should be able to strip PL from the ID. It's a common function on modern Moto radios (nearly all of them either have a dedicated PL defeat pin or a assignable on the accessory connector).

There was a debate about this radio going on under the GMRS page of RR. After some did some digging around in the FCC OET, they found that the emissions designator is for that of Motorola Astro (P25), and that the radio is only rated at 1.1W UHF. Not to mention it's only authorized for UHF. The page has since be removed from the Powerwerx site.

It only has the first 3 splits programmed in from the factory…they could've at least put 675 in there at there factory.

Battery life probably.