[Repeater-Builder] Are people on ebay nuts?
This has to be a joke right? Look at item number, 130377678510 $1,320 are they for real? I really love the missing covers, the bent case and the rust. Adds real class.
[Repeater-Builder] Re: Question about antenna seperation
James, It would be helpful to know if you are planning using cavities and or filtering to help provide the needed isolation. Also knowing what the receiver will be and what the preamp is if any will all play into what is needed to get any real world numbers to determine the required isolation. In my experience with VHF split antenna repeaters, at that power level and using some pretty good filtering, I would expect that you will need in the neighborhood of 80 to 100 feet between the top of the bottom antenna and bottom of the top antenna. This just a guess not knowing the answers to the first two questions. Sounds like a fun project. I prefer a split antenna repeater anytime over a single antenna duplexed repeater. We use 225 Watt Micor UHF repeaters for our ham stuff here on the Oregon Coast. I love the challenges of making the high power stuff work. Joe - WA7JAW --- In Repeater-Builder@yahoogroups.com, James Adkins wrote: > > We are considering installing a 2-meter repeater, standard 600 kHz spacing, > with separate antennas for transmit and receive, looking at phasing together > 2 DB-228's for RX and 2 DB-228's for TX and using a high-power transmitter, > such as a Motorola Nucleus at 250-300w or other high-power transmitter. > > Does anyone have a formula or know what formula would need to be used to > determine the amount of vertical separation needed to provide the isolation > required for such a duplex operation? > > We are wanting separate TX and RX antennas because of plans to have the > repeater on a platform located 1200' in the air, and heliax runs are not > practicable. > > -- > James Adkins, KB0NHX >
[Repeater-Builder] Motorola test&repair jigs for HT 600 and MT 1000 Maybe others I don't know?
I have a new old stock thing I bought from Big M when I had a customer that had these radios. They went with a rental company instead, so it did not get used by me ever. It is an REN 4000A,also I have in that box> 2 of< an NTN 5368a rf adaptor, this thing allows one to open up and unfold the flex circuits and run them out side of the radio cabinet, and a plastic/nylon? device to secure them from the top with holes to access test points I think. Any way It listed for 335$ then, Dealer cost was 298$. any ways its un used in the original box and doc's < a parts list> If any one has some thing to trade for this? or money? let me know at kb5...@yahoo.com Thanks Daryl
[Repeater-Builder] Re: Helper Instruments (Voltadder VA 502)
I think one was called the Lineman? and another the Toner? I added some dtmf and burst tones to my Sinadder 3 with aftermarket stuff from CES and others. --- In Repeater-Builder@yahoogroups.com, "Gary Schafer" wrote: > > Ok, I never saw that one. That was after my time with them. > > There was another small company in Indiana that was started by a couple of > ex wavetek guys that build a line test box too. It would fully simulate DC > and tone remotes, measure line levels etc. Was a pretty nice box but pricey. > I can't remember the name of it now. > > 73 > Gary K4FMX > > > -Original Message- > > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > > buil...@yahoogroups.com] On Behalf Of Dawn > > Sent: Friday, March 26, 2010 4:29 PM > > To: Repeater-Builder@yahoogroups.com > > Subject: [Repeater-Builder] Re: Helper Instruments (Voltadder VA 502) > > > > No Gary. I meant Sineman. I'm fully aware of the lineman. That was a bit > > overpriced for what it did. We had two Nortel units that we bought ex- > > telco that did the same thing elegantly. > > > > The Sineman was a unit that we received a mailed brochure. I'm looking > > at it now. The description: " Microprocessor controlled test set > > features: AC voltmeter,Sineadder,Line Level meter,Single and DTMF tone > > decoding and portable battery operation" $550 for a short time. > > > > The drawing of the unit shows a square box with a large meter and 16 > > digit keypad on the right. Bridge and terminate switch. 4 controls > > labeled Mode, Scale,Vol.,& Level. This doesn't have the typical > > appearance of Helper products. It looks like a keypad entry version of > > the Toner 3,Lineman,Sinadder 3 with DTMF decode added. This arrived > > after Susan took control of the company. I can scan this and upload it > > if anyone is interested. > > > > --- In Repeater-Builder@yahoogroups.com, "Gary Schafer" > > wrote: > > > > > > > > > The idea of the dual meter unit was to be able to quickly go thru a > > circuit > > > without having to touch the meter to change ranges or change to AC or > > DC. If > > > you stuck it on a DC circuit it would read that right. If you stuck it > > on an > > > AC circuit it would read that. > > > Also you could read an AC voltage riding on top of a DC voltage. One > > meter > > > would display the DC and the other the AC value. > > > Kind of handy sometimes. > > > I may have a catalog sheet of it somewhere around here but I haven't > > run > > > across it in some time, > > > > > > Yes the mod box was ok but didn't sell to well. > > > > > > The other item I assume that you meant "lineman". That was a very > > slick box > > > and sold well. It was a line level meter with tone generator and audio > > > amp/speaker and mike. It had the commonly used tone remote tones built > > in so > > > you could check the line level at those frequencies. > > > Usually people bought two of them, one to use on each end of a line > > being > > > tested. You could talk back and forth to the guy on the other end and > > send > > > each other tones and measure levels each way. > > > > > > 73 > > > Gary K4FMX > > > > > > > There were very few combination analog/DVM's at service instrument > > > > prices and the DMM's that had bar graphs didn't have the resoloution > > for > > > > trends at the time. I can only think of a few off hand such as the > > > > Keithly,Simpson had an early one in a 260 type case with > > > > Nixies,Ballentine $, and Fluke . I think Heath had one for a > > > > short time too. I'd love to see a picture of this meter. I'm still > > > > trying to grasp what was so special about two separate meters for AC > > and > > > > DC. There had to be some of Bill's magic either comparator presets, > > > > audible alarm or some neat thing that would make service easier. > > > > > > > > While the subject is odd Helper stuff, remember the Mod Box or the > > > > Sineman? > > > > > > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > >
Re: [Repeater-Builder] Question about antenna seperation
On Fri, 26 Mar 2010, James Adkins wrote: > We are considering installing a 2-meter repeater, standard 600 kHz > spacing, with separate antennas for transmit and receive, looking at > phasing together 2 DB-228's for RX and 2 DB-228's for TX and using a > high-power transmitter, such as a Motorola Nucleus at 250-300w or > other high-power transmitter. Does anyone have a formula or know what > formula would need to be used to determine the amount of vertical > separation needed to provide the isolation required for such a duplex > operation? > We are wanting separate TX and RX antennas because of plans to have the > repeater on a > platform located 1200' in the air, and heliax runs are not practicable. There's a chart on the repeater-builder website from GE's older information. http://www.repeater-builder.com/antenna/thoughts-on-isolation.html http://www.repeater-builder.com/antenna/separation.html In short, you're going to have a lot of coax in use already with a DB-2216. You should still have cans on the receiver side, as well as a notch can (rated for the power level) on the transmit side. You may be able to locate the appropriate notch-type can from paging company surplus. Typically they have 7/16" DIN connectors and are aperture coupled between cans. The receive side will need a notch cavity for the transmitter frequency, and some form of a bandpass filter to prevent other signals from causing front-end overload. Just one DB-228 at 500+ ft HAAT will cover out to 100 miles. There's a repeater 35 miles northeast of my apartment that I can work on an HT in my living room. I sit at about 900 ft AGL; the repeater is at 1300 ft AGL. I can work the machine from the laundromat as well -- at 750 ft AGL. I wish you much luck in this endeavor. It's a big project indeed. -- Kris Kirby, KE4AHR Disinformation Analyst
[Repeater-Builder] Question about antenna seperation
We are considering installing a 2-meter repeater, standard 600 kHz spacing, with separate antennas for transmit and receive, looking at phasing together 2 DB-228's for RX and 2 DB-228's for TX and using a high-power transmitter, such as a Motorola Nucleus at 250-300w or other high-power transmitter. Does anyone have a formula or know what formula would need to be used to determine the amount of vertical separation needed to provide the isolation required for such a duplex operation? We are wanting separate TX and RX antennas because of plans to have the repeater on a platform located 1200' in the air, and heliax runs are not practicable. -- James Adkins, KB0NHX
RE: [Repeater-Builder] RG21AU CABLE
At 07:00 PM 26/03/2010, you wrote: >I have finally tracked down a copy of the original RG-21A/U specification, >and have posted it in the Files section of this Group, in the Coaxial Cable >folder. RG-21A/U became official on 07 September 1955, as MIL-C-17/14. >Then, RG-21A/U was replaced by RG-222/U, AKA MIL-C-17/83, on 28 February >1958. RG-222/U was canceled on 12 August 1983, and its replacement was >M17/162-2, AKA MIL-C-17/162. Both RG-21A/U and RG-222/U are >double-shielded and have a "high-resistance" center conductor, but >M17/162-2 has a silver-coated solid copper center conductor. It seems >quite odd that a "linear attenuator" cable would be replaced by a cable that >has negligible attenuation. > >73, Eric Lemmon WB6FLY Thanks Eric..Reading the spec, it appears they both have a loss of 33db/100 feet at 400 mhz. Most interesting... 73 Doug
RE: [Repeater-Builder] RG21AU CABLE
I have finally tracked down a copy of the original RG-21A/U specification, and have posted it in the Files section of this Group, in the Coaxial Cable folder. RG-21A/U became official on 07 September 1955, as MIL-C-17/14. Then, RG-21A/U was replaced by RG-222/U, AKA MIL-C-17/83, on 28 February 1958. RG-222/U was canceled on 12 August 1983, and its replacement was M17/162-2, AKA MIL-C-17/162. Both RG-21A/U and RG-222/U are double-shielded and have a "high-resistance" center conductor, but M17/162-2 has a silver-coated solid copper center conductor. It seems quite odd that a "linear attenuator" cable would be replaced by a cable that has negligible attenuation. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Doug Sent: Wednesday, March 24, 2010 8:47 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] RG21AU CABLE At 09:26 PM 24/03/2010, you wrote: >Doug, > > From what I have found, RG-21A/U cable is 53 ohm impedance, 0.339" outer >diameter, double silver-plated copper braid shields, and a solid center >conductor of "high resistance wire." The dielectric is solid polyethylene, >and the jacket is black PVC. If you have a sample of this wire, please >reveal what is printed lengthwise on the jacket. > >73, Eric Lemmon WB6FLY Hi Eric. Well it has Plastoid Corportation RG-21/AU on the black jacket. It is stiff coax. You describe it very well. I sort of remember using something like this to reduce the power of an old Prog line unit... Here in Canada they didn't allow us to turn the power down, you had to use an attenuator. Thanks Eric Doug
RE: [Repeater-Builder] Re: Helper Instruments (Voltadder VA 502)
Ok, I never saw that one. That was after my time with them. There was another small company in Indiana that was started by a couple of ex wavetek guys that build a line test box too. It would fully simulate DC and tone remotes, measure line levels etc. Was a pretty nice box but pricey. I can't remember the name of it now. 73 Gary K4FMX > -Original Message- > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > buil...@yahoogroups.com] On Behalf Of Dawn > Sent: Friday, March 26, 2010 4:29 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: Helper Instruments (Voltadder VA 502) > > No Gary. I meant Sineman. I'm fully aware of the lineman. That was a bit > overpriced for what it did. We had two Nortel units that we bought ex- > telco that did the same thing elegantly. > > The Sineman was a unit that we received a mailed brochure. I'm looking > at it now. The description: " Microprocessor controlled test set > features: AC voltmeter,Sineadder,Line Level meter,Single and DTMF tone > decoding and portable battery operation" $550 for a short time. > > The drawing of the unit shows a square box with a large meter and 16 > digit keypad on the right. Bridge and terminate switch. 4 controls > labeled Mode, Scale,Vol.,& Level. This doesn't have the typical > appearance of Helper products. It looks like a keypad entry version of > the Toner 3,Lineman,Sinadder 3 with DTMF decode added. This arrived > after Susan took control of the company. I can scan this and upload it > if anyone is interested. > > --- In Repeater-Builder@yahoogroups.com, "Gary Schafer" > wrote: > > > > > > The idea of the dual meter unit was to be able to quickly go thru a > circuit > > without having to touch the meter to change ranges or change to AC or > DC. If > > you stuck it on a DC circuit it would read that right. If you stuck it > on an > > AC circuit it would read that. > > Also you could read an AC voltage riding on top of a DC voltage. One > meter > > would display the DC and the other the AC value. > > Kind of handy sometimes. > > I may have a catalog sheet of it somewhere around here but I haven't > run > > across it in some time, > > > > Yes the mod box was ok but didn't sell to well. > > > > The other item I assume that you meant "lineman". That was a very > slick box > > and sold well. It was a line level meter with tone generator and audio > > amp/speaker and mike. It had the commonly used tone remote tones built > in so > > you could check the line level at those frequencies. > > Usually people bought two of them, one to use on each end of a line > being > > tested. You could talk back and forth to the guy on the other end and > send > > each other tones and measure levels each way. > > > > 73 > > Gary K4FMX > > > > > There were very few combination analog/DVM's at service instrument > > > prices and the DMM's that had bar graphs didn't have the resoloution > for > > > trends at the time. I can only think of a few off hand such as the > > > Keithly,Simpson had an early one in a 260 type case with > > > Nixies,Ballentine $, and Fluke . I think Heath had one for a > > > short time too. I'd love to see a picture of this meter. I'm still > > > trying to grasp what was so special about two separate meters for AC > and > > > DC. There had to be some of Bill's magic either comparator presets, > > > audible alarm or some neat thing that would make service easier. > > > > > > While the subject is odd Helper stuff, remember the Mod Box or the > > > Sineman? > > > > > > > > > > > > > > Yahoo! Groups Links > > >
[Repeater-Builder] Re: Helper Instruments (Voltadder VA 502)
No Gary. I meant Sineman. I'm fully aware of the lineman. That was a bit overpriced for what it did. We had two Nortel units that we bought ex-telco that did the same thing elegantly. The Sineman was a unit that we received a mailed brochure. I'm looking at it now. The description: " Microprocessor controlled test set features: AC voltmeter,Sineadder,Line Level meter,Single and DTMF tone decoding and portable battery operation" $550 for a short time. The drawing of the unit shows a square box with a large meter and 16 digit keypad on the right. Bridge and terminate switch. 4 controls labeled Mode, Scale,Vol.,& Level. This doesn't have the typical appearance of Helper products. It looks like a keypad entry version of the Toner 3,Lineman,Sinadder 3 with DTMF decode added. This arrived after Susan took control of the company. I can scan this and upload it if anyone is interested. --- In Repeater-Builder@yahoogroups.com, "Gary Schafer" wrote: > > > The idea of the dual meter unit was to be able to quickly go thru a circuit > without having to touch the meter to change ranges or change to AC or DC. If > you stuck it on a DC circuit it would read that right. If you stuck it on an > AC circuit it would read that. > Also you could read an AC voltage riding on top of a DC voltage. One meter > would display the DC and the other the AC value. > Kind of handy sometimes. > I may have a catalog sheet of it somewhere around here but I haven't run > across it in some time, > > Yes the mod box was ok but didn't sell to well. > > The other item I assume that you meant "lineman". That was a very slick box > and sold well. It was a line level meter with tone generator and audio > amp/speaker and mike. It had the commonly used tone remote tones built in so > you could check the line level at those frequencies. > Usually people bought two of them, one to use on each end of a line being > tested. You could talk back and forth to the guy on the other end and send > each other tones and measure levels each way. > > 73 > Gary K4FMX > > > There were very few combination analog/DVM's at service instrument > > prices and the DMM's that had bar graphs didn't have the resoloution for > > trends at the time. I can only think of a few off hand such as the > > Keithly,Simpson had an early one in a 260 type case with > > Nixies,Ballentine $, and Fluke . I think Heath had one for a > > short time too. I'd love to see a picture of this meter. I'm still > > trying to grasp what was so special about two separate meters for AC and > > DC. There had to be some of Bill's magic either comparator presets, > > audible alarm or some neat thing that would make service easier. > > > > While the subject is odd Helper stuff, remember the Mod Box or the > > Sineman? > > >
Re: [Repeater-Builder] Maxtrac Channel Control
On Fri, 26 Mar 2010, Mike Morris WA6ILQ wrote: > As far as I know the early Maxtrac did not implement "Channel > Steering" (Motos' name for binary channel selection). You needed to > use a late Maxtrac (more precisely one with the late logic board), a > Radius LRA series or a GM300 to get that feature, and then you had to > do some very careful programming of the radio to get 4 bits of channel > steering, a RUS pin, and a transmit PL encoder on/off pin. What does this look like in RSS? Is it specified in the pin selection? I looked in a recent Radius firmware and didn't see anywhere that I could enable or disable channel steering by the pins. -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] Re: Helper Instruments (Voltadder VA 502)
The idea of the dual meter unit was to be able to quickly go thru a circuit without having to touch the meter to change ranges or change to AC or DC. If you stuck it on a DC circuit it would read that right. If you stuck it on an AC circuit it would read that. Also you could read an AC voltage riding on top of a DC voltage. One meter would display the DC and the other the AC value. Kind of handy sometimes. I may have a catalog sheet of it somewhere around here but I haven't run across it in some time, Yes the mod box was ok but didn't sell to well. The other item I assume that you meant "lineman". That was a very slick box and sold well. It was a line level meter with tone generator and audio amp/speaker and mike. It had the commonly used tone remote tones built in so you could check the line level at those frequencies. Usually people bought two of them, one to use on each end of a line being tested. You could talk back and forth to the guy on the other end and send each other tones and measure levels each way. 73 Gary K4FMX > There were very few combination analog/DVM's at service instrument > prices and the DMM's that had bar graphs didn't have the resoloution for > trends at the time. I can only think of a few off hand such as the > Keithly,Simpson had an early one in a 260 type case with > Nixies,Ballentine $, and Fluke . I think Heath had one for a > short time too. I'd love to see a picture of this meter. I'm still > trying to grasp what was so special about two separate meters for AC and > DC. There had to be some of Bill's magic either comparator presets, > audible alarm or some neat thing that would make service easier. > > While the subject is odd Helper stuff, remember the Mod Box or the > Sineman? >
RE: [Repeater-Builder] Re: Helper Instruments (Voltadder VA 502)
> Gary: The guy that marketed that 40 db power pad was actually a rep, > a real character. I still have the data sheet and picture somewhere > here in my library. He used to tell me his real money came from > making and selling waders. > > BTW I do have the schematic and JPEG of the Cushman 40 db pad with > the fuse inside. Should I send it to someone? > > Ciao, Tony, K3WX > > > > 73 > > Gary K4FMX Hi Tony, That was Don Simons. I think that he is still a rep but last I heard from him he was in Loveland, Co. He even left the rep business for a few years selling his waders. :>) 73 Gary K4FMX
[Repeater-Builder] Re: Anyone try the "new" ID-O-Matic 2?
Have the original in use on a 2 meter repeater - it works fine - I love the serial programming for the ID and parameters. Can't do it remote, but I have not had a need to. I will be getting one of the new models sometime to play with. One comment - he does have protection on the two main inputs but there are some that are directly to the PIC - he warns not to exceed 5 volts on those - believe me - he isn't kidding - the chip can be blown INSTANTLY - I know from experience. Great little product - the new version has several worthwhile improvements and at $25 it's hard to beat. 73 - Dan --- In Repeater-Builder@yahoogroups.com, "kd8biw" wrote: > > I've not tried the ID2, but I do have the original ID-O-Matic and the > connector interface hooked to 2 Maxtrac UHF mobiles configured as a portable > repeater. It works very well, sounds great, and was easy to assemble and > install! I have maybe an hour total in assembly, wiring, programming, and > tuning. I'm sure the ID2 will be just as good! > > Steve KD8BIW > > KD8BIW/R 224.580 > KD8BIW/R 443.500 (Portable) > N8IHI/R 147.105 > W3YXS/R 146.745 > KD8JBF/R 444.325 > > --- In Repeater-Builder@yahoogroups.com, AJ wrote: > > > > http://www.hamgadgets.com/store/product_info.php?products_id=108 > > > > Looks like it might be a very -very- _very_ simple option for a temp > > repeater setup.. > > >
Re: [Repeater-Builder] Maxtrac Channel Control
As far as I know the early Maxtrac did not implement "Channel Steering" (Motos' name for binary channel selection). You needed to use a late Maxtrac (more precisely one with the late logic board), a Radius LRA series or a GM300 to get that feature, and then you had to do some very careful programming of the radio to get 4 bits of channel steering, a RUS pin, and a transmit PL encoder on/off pin. Be careful what you program into your remote base even if you are the only one at a site. I found out the hard way that 147.51 takes out a repeater with a 442.525 input (do the math). If you have a busy site it gets even worse. Radios with plastic cases (i.e. leaky synthesizers) have gotten a few friends in hot water with various site managers. Remember that something that passes spec for type acceptance can still leak enough to be heard in an adjacent rack. Mike WA6ILQ At 11:04 PM 03/25/10, you wrote: >Hello everyone, > >Wondering if anyone has been able to implement a Motorola Maxtrac as >a "frequency agile" remote base on a repeater. What I would like to >do is have a 16 channel VHF mobile hooked to our repeater, and be >able to select a channel at will. I'm sure it can be done, i'm just >overlooking something here. Our controller has a 4 pin hex output >that I think could do the necessary stuff to make it work, just not >sure about how it needs hooked to the radio. Has anyone done >something similiar to this? I was looking at NO6B's RBI, and that >would fit the bill, just wondering if I could make it work with our >controller (MCC RC-100) or would I have to get a different >controller (CAT or LinkCom)? Thanks all! > >Steve KD8BIW > >KD8BIW/R 224.580 >N8IHI/R 147.105 >W3YXS/R 146.745 >KD8JBF/R 444.325 > > > > > > > >Yahoo! Groups Links > > >
[Repeater-Builder] Re:Maxtrac Channel Control
On Thu Mar 25, 2010 11:04 pm (PDT) "kd8biw" kd8...@hotmail.com wrote: >Wondering if anyone has been able to implement a Motorola Maxtrac as a >"frequency agile" remote base on a repeater. What I would like to do is have >a 16 channel VHF mobile hooked to our repeater, and be able to select a >channel at will. I'm sure it can be done, i'm just overlooking something >here. Our controller has a 4 pin hex output that I think could do the >necessary stuff to make it work, just not sure about how it needs hooked to >the radio. Has anyone done something similiar to this? I was looking at >NO6B's RBI, and that would fit the bill, just wondering if I could make it >work with our controller (MCC RC-100) or would I have to get a different >controller (CAT or LinkCom)? Thanks all! It depends on what board and software version your Maxtrac has in it. M used the Maxtrac name for a number of different radios in different markets. If it has a 16-pin accessory connector (trunked Maxtracs only had a 5 pin accessory connector) then check the RSS to see if you can assign the pins functions. On the 2 layer logic board you couldn't, but on radios with the 4- layer logic board you could. Several of the lines can be used for channel steering. From memory the format was BCD, rather than straight hex, but my recollection could be faulty - it's been >10 years since I've looked at one. Check out the batlabs web site - you'll find lots of info there that may be helpful. Rodney. -- === Rodney Baker VK5ZTV rodney.ba...@iinet.net.au ===
Re: [Repeater-Builder] Maxtrac Channel Control
On Mar 26, 2010, at 12:04 AM, kd8biw wrote: > Hello everyone, > > Wondering if anyone has been able to implement a Motorola Maxtrac as a > "frequency agile" remote base on a repeater. What I would like to do is have > a 16 channel VHF mobile hooked to our repeater, and be able to select a > channel at will. I'm sure it can be done, i'm just overlooking something > here. Our controller has a 4 pin hex output that I think could do the > necessary stuff to make it work, just not sure about how it needs hooked to > the radio. Has anyone done something similiar to this? I was looking at > NO6B's RBI, and that would fit the bill, just wondering if I could make it > work with our controller (MCC RC-100) or would I have to get a different > controller (CAT or LinkCom)? Thanks all! > > Steve KD8BIW > > KD8BIW/R 224.580 > N8IHI/R 147.105 > W3YXS/R 146.745 > KD8JBF/R 444.325 Don't know about Maxtracs, but plenty of folks have done channelized remote bases and even completely frequency-agile ones. A couple of things to watch out for: - If you're repeater is VHF and your remote base is VHF... look out! You're putting a (relatively) high power transmitter very near your repeater input frequency. If you don't directly desense your repeater input, you can certainly hit "mixes" with nearby transmitters on the site and do it, and/or just clobber other mountain-top "neighbors" with repeaters in your target band. Be as careful picking the frequencies you'll ALLOW your remote base to operate on, as the site manager would when doing a transmitter site survey and calculating all of the mixes, 3rd and 5th order harmonics, etc. - If your repeater is in another band other than your remote base, that's better for you, but calculate and think about the "neighbors" if there are any, same as the above. Also watch out for 3rd order harmonics if you're doing VHF on one and UHF on the other. - I've read articles about radios LIKE the Maxtrac that have a microphone up/down switch just being directly triggered by the controller with a single logic-level output line. No need for a fancy remote base interface. However, think about how to "find" channel 1 if you ever get the controller and rig out of "synch" on button-presses. Many rigs can be programmed to always power up on a particular channel in the commercial options (like the Maxtrac, I believe... but a Moto programming expert would have to clarify the options with that particular rig), and making sure to wire up a way to "bounce" the power to the remote base rig on top of the remote channel switching circuitry, is in order. - Similar to the above... if the RB radio locks up in TX or RX with some new mix or a bad "neighbor" at the site... make sure you don't just have a way to disconnect it's audio from the controller, make sure you have a way to POWER IT OFF remotely, if any sort of failure occurs. There's nothing madder than a site manager calling saying your remote base mobile in your cabinet has been determined to be the culprit, is stuck in transmit, and the only way to the site is a snow-cat or snowmobile in the dead of winter. (I know, you're probably in 8-land if your callsign matches your district still, and don't have that limited access to your repeater site... but think it through if you have anything that limits access as to how you'll "failsafe" the whole system. (Applies to the repeater itself, too... really.) - Mobiles have terrible shielding, typically. Many sites here BAN mobile rigs used in cabinets completely. The reason? IF leakage can mix with other IF's on site and create havok. Commercial quality repeaters typically have GOOD shielding with a metal box all the way 'round the exciter, receiver, and everything but the Power Amplifier stage. It can then, of course, be grounded, and act as a mini Faraday Cage around the noisy microprocessor (inevitable) of a synthesized rig, the IF of the rig, etc. At the very least, make sure the CASE of whatever mobile you use (if you must use a mobile) is grounded properly. Keep the RF noise INSIDE the radio. Granted many Amateur repeaters (here's looking at you Icom/D-STAR!) have even less shielding than a typical commercial mobile rig, and/or have leaky internal coax jumpers that will both let RF out, and into, the repeater... Those are just some thoughts about using mobiles (and worse, ham mobiles) as remote bases at busy RF sites. If you're at a site with few radios, and know the other repeater/system operators well, have them give you a heads up as to what frequencies they're using, and stay away from their input frequencies, harmonics/multiples there-of, etc... and likewise, pre-plan your frequencies appropriately when trying not to wipe yourself out, too. Hopefully that helps spark your thoughts as to how to properly engineer a remote base. I know nothing about your MCC, but perhaps the note about pulsing a single pin will bring som
