The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!
A friend of mine acquired this unit, I have a general idea of what it is, it has an HT90 board in it, but i'm looking for a little more info on it. Is this unit an actual low power repeater in itself, or is there something missing from it? Does anyone have any experience with these things? It's a model #k34LCF1102BP.
I looked on the batlabs section on it, but i'm having trouble understanding what is here and what's missing.
Heres some pics:
If anyone can just identify what I have and what else is needed, it would be greatly appreciated. I'd like to tinker around with this, but I don't wanna blow it up...... yet
You can gather a few things from this picture. First, without knowing knowing the pinout, the radio appears to be half duplex and I am going to make some guesses.
1: Your audio in and out is on pins one and two. That's why it's red and green, typical of the pairs for a piece of station wire.
2: PTT is on pin five, the yellow lead. My guess is to combine that with the black lead and you will make it transmit.
There does not appear to be a carrier detect arrangement delivered out of the box. So, it appears to be a PTT driven, no carrier detect provided, two wire arrangement to drive a remote base or something like that.
I would try putting a signal into it with a service monitor and see if you get audio on red/green. If you get that, then try shorting the yellow/black and see if it transmits. It you are chicken, try looking at the power voltage and use a current regulated power supply to limit the current if this is wrong, thus avoiding damage.
You can figure this out. I have full faith and confidence.
Wake me again when it's time for me to poop my guts out due to food poisioning. I hate that stuff. I have been doing that since Friday when I was awakened at work to do so. Nobody should be disturbed like that.
I saw similar innards in highway callboxes back in the late '60s early '70s.
What you have looks like the part that was mounted inside a heavy metal housing that was mounted on light poles every 1/4 - 1/2 mile along I-45 in Houston (and elsewhere, I'm sure).
That's my guess. The guts of an emergency callbox.
Yes, it is an rf link capable of simplex ptt operation or tx only for one way link. I had two of them in service here until about 2 years ago. That green wire on terminals 1 & 10 is for tx only. PTT is #1 and Ground is #10. Tx audio is #5 & #6, Rx audio is # 8 & #9. The rf portion is just an HT90 as you have determined. Also a small interface board in the radio box with 14 pin connector, adjustment pots, and led's. If you want a pdf of these extra boards, I'll scan and send to you.
To expand a little on what these were used for (one thing at least, there may be more), they were hooked to another radio to create an RF-based "extension" of a radio system, if that makes any sense. The shortline railroad I used to work for has a pair. They are on standard AAR frequencies (all VHF, in the 161 MHz range), with a main radio (MSF5000) remotely controlled (tone) over a leased-line. The MSF is set up for four channels. There is a small tone-remote chassis (I forget who makes it, but its simply a unit that plugs into a phone pair to get tones and connects to a radio to allow it to be remotely controlled) also piggy-backed on the same leased-line, and configured to respond to the correct tone for "channel five". If channels one through four are selected on the console in the dispatch office, the MSF responds. If channel five is selected, the secondary chassis responds. It is hooked to an RF Link unit similar to yours (except its a little newer and uses a GP300 chassis instead of an HT90), which transmits on UHF to another RF Link with the TX and RX reversed from the unit at the main radio. That one is hooked to the accessory connector of an M120. Gives them another remote base over 20 miles further down the line from the main radio without the added expense (and headache) of another leased-line.
kf4sqb wrote:To expand a little on what these were used for (one thing at least, there may be more), they were hooked to another radio to create an RF-based "extension" of a radio system, if that makes any sense. The shortline railroad I used to work for has a pair. They are on standard AAR frequencies (all VHF, in the 161 MHz range), with a main radio (MSF5000) remotely controlled (tone) over a leased-line. The MSF is set up for four channels. There is a small tone-remote chassis (I forget who makes it, but its simply a unit that plugs into a phone pair to get tones and connects to a radio to allow it to be remotely controlled) also piggy-backed on the same leased-line, and configured to respond to the correct tone for "channel five". If channels one through four are selected on the console in the dispatch office, the MSF responds. If channel five is selected, the secondary chassis responds. It is hooked to an RF Link unit similar to yours (except its a little newer and uses a GP300 chassis instead of an HT90), which transmits on UHF to another RF Link with the TX and RX reversed from the unit at the main radio. That one is hooked to the accessory connector of an M120. Gives them another remote base over 20 miles further down the line from the main radio without the added expense (and headache) of another leased-line.
This sounds pretty cool. How was the audio quality of this remote base?
Audio quality was great. As long as the levels on the leased-line feeding the tone-remote chassis at the main radio site were correct, it sounded the same as the main radio. In fact, I went back later and expanded it. I took the VHF M120 from the extended site and put a UHF M1225 in it's place with it's TX/RX frequencies the reverse of whats in the RF Link unit. The M120 was moved another 15 miles or so down the line and connected to another UHF M1225 that was set up to talk to the M1225 at the original site. Worked great!
