Hello, Many years ago I built crossband radio setup going from a simplex PPL 6060 to a EF Johnson 800 MHz trunk radio. The simplex PPL 6060 was not good enough so I built a full duplex mobile repeater out of another EF Johnson PPL 6060 on one of the old splinter channels. I had a 16 function Touch Tone decoder controlling a E F Johnson 800 MHz trunking radio in my truck that also carried two batteries. I had a Phelps Dodge, Cellwave whatever 4 cavity mobile duplexer feeding a antenna mounted under the truck which most of the time gave me good enough coverage to go inside large building without a lot of dead spots. If I needed more coverage I just stuck a mag mount antenna on top of the truck, along side the other 5 antennas <grin>. I could change systems or groups, go to the phone patch, turn the trunk radio off or inhibit the transmitter so I could use the repeater locally without bothering the office. I still have the PPL 6060 that's now on a Ham repeater frequency with the Touch Tone controller but the trunk system has gone the way of NEXTEL unfortunately!
It was fun to build and use! Who cares if it was legal or not, besides they can't get me now, the statute of limitations is past now! Actually we had licenses on all frequencies and the FCC did not care what you did with the splinter channels at the time, or so the lawyer said! Paul WB5IDM -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] Behalf Of mch Sent: Thursday, July 28, 2005 1:18 AM To: [email protected] Subject: Re: [Repeater-Builder] Re: Mobile Repeaters Actually most mobile repeaters are simplex so you can TX and RX on the same frequency and use your portable with the power of the mobile the mobile repeater is connected to. All you would need is a simplex single band (even one channel) HT. The better ones (such as the Motorola PAC series) will have sampling of the frequency so you can even use them on repeaters without waiting for the tails to drop. You can even key up if your mobile is hearing a distant station, or even if a distant station is getting into the repeater you are trying to work. It's just like using the mic on the mobile itself. What you are describing is a cross-band repeater where the mobile receives on one band and transmits on another. BTW, as for coordination, in WPA there is a band segment just for mobile repeaters. That keeps them off the link frequencies. Joe M. w4cng wrote: > > Ditto: There are lots of dual band mobiles and at least one dualband > HT that have repeater capability. These are not true Mobile > Repeaters. A "Mobile Repeater" is a device (usually custom built) > that has 1-2 input frequencies plus tone that repeat out to several > selected repeater input frequencies. You also need a HT rig with > custom Offset TX frequncies to talk to the Mobile Repeater while > listening to the output frequency of the Repeater you want to work. > You also need the ability to have 40-50db Isolation between the input > and output frequencies of the mobile repeater to make it work. This > will include some specially tuned cavity filters (small) and at least > two antennas, one for RX and one for TX. If any of this does not > ring a bell with what you have seen, worked on, or have in your > posession, then it may be over your head to do/use other than learn > and do over a period of years. My mobile repeater is a Lafayette > Radio HA-146 25 Watt Crystal Mobile rig split into two custom built > shielded boxes with an interconnecting shielded/filtered cable > between the two boxes. The RX has 2 input frequencies with PL > access, and the TX output is 12 crystal controlled repeater input > frequencies. TX power is 7 watts output. All I have to do is figure > out which repeater I want to work where I am located with the best > signal! The antennna in/out are BNC Female connnectors. Power draw > is 4A TX from 12VDC. RX Filtering is custom built copper cavities (no > pix or drawings). This is where you put in the time (years) to > learn, build, and gain the functional knowledge of repeaters in real > world and all of it's problems. There are no short cuts to move to > the head of the line in this discipline. You learn, apply, fix and > pay your dues. > Good Luck with learning about Repeaters and RF Engineering. > Steve W4CNG building Ham repeaters since 1970. > > > --- In [email protected], "Coy Hilton" <[EMAIL PROTECTED]> > wrote: > > HI Nick, > > I'm going to say this as nicely as I can. > > "Mobile repeaters" are for the most part, completely useless. Most > > coordinators want to know exactly where you are going to put your > > repeater before they will Coordinate a Freequency pair. Mobile > > repeters are at their best as emergency repeaters for remote > > locations in disasters, or special events. > > > > Second, There are now in most places.....medium to large cities, > Way > > more repeaters than necessary, and nearly as many as there are > hams. > > That means MOST machines that people put large amounts of money and > > time into NEVER get used. > > > > Third, If you have to ask for detailed info on how to obtain parts, > > put togeather and how a repeater works you are not ready to own a > > repeater. You should study, read a lot of old posts from this site, > > and ask local hams in your area about building and owning > repeaters, > > before thinking about owning a repeater. There are already too many > > repeater owners that aren't technical enough to own a repeater and > > thier machines sound like ...well, crap. If you are serious about > > owning a decent machine and put the time into it that it deserves, > > and when you can answer the questions that you asked in your post > > then GOOD LUCK! > > > > 73 > > AC0Y > > > > > > > > --- In [email protected], "ncamilli" <[EMAIL PROTECTED]> > > wrote: > > > Hi. I am new to building/owning my own repeater. What is needed > to > > > complete a mobile repeater? What parts do I need, where can I buy > > > them, and how much will it run me? Thanks in advance. > > > > > > -- > > > Nick > > > Yahoo! Groups Links > > > > Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
