Re: [Repeater-Builder] Re: Building a repeater from Motorola VHF portable
At 08:26 AM 2/19/05, you wrote: >Would a Motorola PAC RT work? In a word, NO. A PAC-RT is a unit designed to extend a mobile radio to a handheld. Picture a highway patrol officer that is out writing a ticket - the handheld on his belt talks to his patrol car and the PAC-RT there is hooked to his regular mobile radio. Think of a simplex autopatch but with an underdash or trunk mounted mobile radio in place of the phone line. It is a crossband* unit with an output power of 1/10 watt ... some were 1/4 of a watt, but not many. There is no duplex ability at all. * crossband: receiving and transmitting on a different band The patrol car mobile and the officer's HT are on totally different bands. The PAC-RTs were built around an RF package based on a low-end handheld, and models were available in the 150mhz and 450 bands. The basic idea of "extending" an existing mobile radio into a mobile crossband repeater is still in wide use. For example, here in California our highway patrol mobiles run on hilltop repeaters with a 42-43mhz output and a 39mhz input. The officer's handhelds are on high band. Mike WA6ILQ 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/
[Repeater-Builder] Re: Building a repeater from Motorola VHF portable
If my life was dependent on it and it was make shift or nothing I will go with make shift any day! I Have built emergency repeaters from HTs before. In an emergency You cant wait for the slow moving dog response of a chief, a city manager ect. to order you a repeater, and a manufacturer to build it and to get it shipped by turtle back express. You have to have something NOW! I was involved with public safety communications for over ten years. I've seen Police departments go totaly with out communications in a matter of minutes. It's a spooky situation to be in, not to mention how it feels for the Police Officer. In this day and time they can't be with out communications for more than a few seconds. Just think how much NEXTEL is going to pay to fix the situation that they're in with public safety communications. --- In Repeater-Builder@yahoogroups.com, Eric Lemmon <[EMAIL PROTECTED]> wrote: > Denny, > > The R1225 is just the full-duplex transceiver that is in a GR1225 or > RKR1225 repeater cabinet. It is exactly the same size as a Maxtrac or > GM300 dash-mount mobile radio. Since it has a built-in controller, all > you need is a duplexer and the connecting cables and you have a tactical > repeater. I have done this, and it works very well. There are many > issues to consider when creating a full-duplex repeater from two simplex > handheld radios, and I don't think you should pursue such a solution- > especially since this is intended to be used where people's lives may be > at risk. A PAC-RT is not appropriate for this application. > > 73, Eric Lemmon WB6FLY > > Denny wrote: > > > > Thanks for the input. It is 150MHz and we would have a 5Mhz split. > > What is the best process for shielding the two radios? Are there > > cases out there or some foil type products? What would happen if we > > just connected to the two radios together and separated the antennas? > > > > I looked at the R1225 and it is a little big but may work if need > > be. Would a Motorola PAC RT work? > > > > Denny > > > > --- In Repeater-Builder@yahoogroups.com, Eric Lemmon <[EMAIL PROTECTED]> > > wrote: > > > Denny, > > > > > > The HT1000 is an excellent radio by itself, but its plastic case > > offers > > > no shielding whatsoever. It is possible to construct a compact low > > > power repeater with the HT1000 (or any two commercial quality > > portable > > > radios) if each radio is enclosed in a tightly-shielded box, with > > all > > > audio and control leads brought out through coaxial filter > > capacitor > > > terminals. The antenna lead would need to be brought out through a > > > separate bulkhead connector. > > > > > > Once you have a completely shielded transmitter and a completely > > > shielded receiver, connect them to a compact (mobile) duplexer with > > > double-shielded cable such as RG-400/U. You will need a > > rudimentary > > > controller to handle the simple repeater functions. I am assuming > > that > > > the pair you intend to use in the 150 MHz VHF band has a 5 MHz > > split; if > > > it is less, a mobile duplexer won't work. > > > > > > It would be a lot easier to use a 10 watt Motorola R1225 repeater > > > transceiver, instead of two separate radios. > > > > > > 73, Eric Lemmon WB6FLY > > > > > > > > > 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/
Re: [Repeater-Builder] Re: Building a repeater from Motorola VHF portable
If you don't need a lot of power look at the Kenwood TKR-740we use a lot of the tkr840 and love them. John - Original Message - From: "Denny" <[EMAIL PROTECTED]> To: Sent: Saturday, February 19, 2005 11:26 AM Subject: [Repeater-Builder] Re: Building a repeater from Motorola VHF portable > > > > Thanks for the input. It is 150MHz and we would have a 5Mhz split. > What is the best process for shielding the two radios? Are there > cases out there or some foil type products? What would happen if we > just connected to the two radios together and separated the antennas? > > I looked at the R1225 and it is a little big but may work if need > be. Would a Motorola PAC RT work? > > Denny > > --- In Repeater-Builder@yahoogroups.com, Eric Lemmon <[EMAIL PROTECTED]> > wrote: >> Denny, >> >> The HT1000 is an excellent radio by itself, but its plastic case > offers >> no shielding whatsoever. It is possible to construct a compact low >> power repeater with the HT1000 (or any two commercial quality > portable >> radios) if each radio is enclosed in a tightly-shielded box, with > all >> audio and control leads brought out through coaxial filter > capacitor >> terminals. The antenna lead would need to be brought out through a >> separate bulkhead connector. >> >> Once you have a completely shielded transmitter and a completely >> shielded receiver, connect them to a compact (mobile) duplexer with >> double-shielded cable such as RG-400/U. You will need a > rudimentary >> controller to handle the simple repeater functions. I am assuming > that >> the pair you intend to use in the 150 MHz VHF band has a 5 MHz > split; if >> it is less, a mobile duplexer won't work. >> >> It would be a lot easier to use a 10 watt Motorola R1225 repeater >> transceiver, instead of two separate radios. >> >> 73, Eric Lemmon WB6FLY >> > > > > > > > > > > > > > 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/
Re: [Repeater-Builder] Re: Building a repeater from Motorola VHF portable
Denny, The R1225 is just the full-duplex transceiver that is in a GR1225 or RKR1225 repeater cabinet. It is exactly the same size as a Maxtrac or GM300 dash-mount mobile radio. Since it has a built-in controller, all you need is a duplexer and the connecting cables and you have a tactical repeater. I have done this, and it works very well. There are many issues to consider when creating a full-duplex repeater from two simplex handheld radios, and I don't think you should pursue such a solution- especially since this is intended to be used where people's lives may be at risk. A PAC-RT is not appropriate for this application. 73, Eric Lemmon WB6FLY Denny wrote: > > Thanks for the input. It is 150MHz and we would have a 5Mhz split. > What is the best process for shielding the two radios? Are there > cases out there or some foil type products? What would happen if we > just connected to the two radios together and separated the antennas? > > I looked at the R1225 and it is a little big but may work if need > be. Would a Motorola PAC RT work? > > Denny > > --- In Repeater-Builder@yahoogroups.com, Eric Lemmon <[EMAIL PROTECTED]> > wrote: > > Denny, > > > > The HT1000 is an excellent radio by itself, but its plastic case > offers > > no shielding whatsoever. It is possible to construct a compact low > > power repeater with the HT1000 (or any two commercial quality > portable > > radios) if each radio is enclosed in a tightly-shielded box, with > all > > audio and control leads brought out through coaxial filter > capacitor > > terminals. The antenna lead would need to be brought out through a > > separate bulkhead connector. > > > > Once you have a completely shielded transmitter and a completely > > shielded receiver, connect them to a compact (mobile) duplexer with > > double-shielded cable such as RG-400/U. You will need a > rudimentary > > controller to handle the simple repeater functions. I am assuming > that > > the pair you intend to use in the 150 MHz VHF band has a 5 MHz > split; if > > it is less, a mobile duplexer won't work. > > > > It would be a lot easier to use a 10 watt Motorola R1225 repeater > > transceiver, instead of two separate radios. > > > > 73, Eric Lemmon WB6FLY > > > > > 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/
[Repeater-Builder] Re: Building a repeater from Motorola VHF portable
Thanks for the input. It is 150MHz and we would have a 5Mhz split. What is the best process for shielding the two radios? Are there cases out there or some foil type products? What would happen if we just connected to the two radios together and separated the antennas? I looked at the R1225 and it is a little big but may work if need be. Would a Motorola PAC RT work? Denny --- In Repeater-Builder@yahoogroups.com, Eric Lemmon <[EMAIL PROTECTED]> wrote: > Denny, > > The HT1000 is an excellent radio by itself, but its plastic case offers > no shielding whatsoever. It is possible to construct a compact low > power repeater with the HT1000 (or any two commercial quality portable > radios) if each radio is enclosed in a tightly-shielded box, with all > audio and control leads brought out through coaxial filter capacitor > terminals. The antenna lead would need to be brought out through a > separate bulkhead connector. > > Once you have a completely shielded transmitter and a completely > shielded receiver, connect them to a compact (mobile) duplexer with > double-shielded cable such as RG-400/U. You will need a rudimentary > controller to handle the simple repeater functions. I am assuming that > the pair you intend to use in the 150 MHz VHF band has a 5 MHz split; if > it is less, a mobile duplexer won't work. > > It would be a lot easier to use a 10 watt Motorola R1225 repeater > transceiver, instead of two separate radios. > > 73, Eric Lemmon WB6FLY > 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/
[Repeater-Builder] Re: Building a repeater from Motorola VHF portable
--- In Repeater-Builder@yahoogroups.com, "Denny" <[EMAIL PROTECTED]> wrote: I am with a law enforcement agency and we have recently > killed our tactical repeater Was it attacking? Was it self defense? Laryn K8TVZ 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/
