VHF Remote Radio Questions

I think you'll find that the base station location is specified on the license. I don't think there's a jurisdiction in the world that will let you relocate without proper authorization. It's all part of frequency use planning. They might well want a frequency change for the new location.

I have

You need a leased voice frequency line, a proper controller at the office end, and proper remote interface equipment at the base station end. Alternatively, you might use a UHF or microwave link. This all needs approved equipment and is pretty damn' expensive.

If you need to ask these questions, it suggests to me that you don't know enough about what you're trying to do to be competent, or legally authorized.

Consult a properly licensed engineer with the proper knowledge and test equipment.

Thanks for your concern, but I believe I mentioned that any bureaucratic hurdles should not be a problem.

As I mentioned, I can use either a DS0 or an RS-232 line, both of which exist and are available for the project. Microwave and UHF are out, as there is no line of sight. This is why I did not mention those alternatives. "Proper" equipment is the reason I made the post; I was hoping someone with specific knowledge could point me to same.

Your answers suggest to me that you would rather preach than offer assistance. Have you never met an engineer who needed help with a technical task? The fact that I need to ask these questions only points out a lack of specific familiarity with specific equipment.

All's well. I believe that I have dreamed up a solution while camping out this weekend. Kind of how a properly licensed engineer might solve a problem - throw out feelers for suggestions, then ponder the problem while relaxing a bit on holiday. The fending off of unconstructive criticisms is all part of the day's work, I suppose.

Thanks anyway. Oh, and I do have a bit of TE lying about. No worries, mate.

I may be able to help, but I need you to define what you call a DS0. DS0 is only a 64kbit/s capability or capacity. Are you trying to say you have a channel in a digital facility available to you? If so, what type of channel unit does it have? What are the characteristics of the voice frequency interfaces to the TX and RX and how is the TX currently keyed?

Don

You and I are defining DS0 in the same way. I don't know the specifics of the particular line, I've only been told that it's availible for use if I can use it. As I mentioned in another newsgroup, this is a low-priority project, almost a spare-time activity. I will investigate the characteristics of the line in the next few days. Thanks for your questions. Some further info:

The radio is a Kenwood TK-720. Today we mulled the possibility of breaking the line at the KMC-18 DTMF mic input, and multiplexing voice and a PTT tone onto our transmission line up to the relocated base. The drawback is that we won't be able to change channels, but we can live with that. We only use two, and we have interesting plans for remote access to the other channel (mwahahahaha!). I've also been looking at some turn-key solutions from online companies, but that would require budget begging, and it would be neat if we can do this as an in-house, shoe-string project.

(Just for clarity, I've started the process for asking for a change on the license, although we won't be done with this for some time. Also, I have a class 2 FCC license, so I'm allowed to play with the XMTR ;-)

I'll post again after I've had a chance to investigate our Cisco network that supplies the now-empty DS0 line to the top of the hill. Thanks again for your input.

If you get a choice of channel unit types, consider an E&M 4-wire unit. This will provide total isolation between the transmit and receive paths for both the audio and the DC signaling voltages (TX transmit and RX squelch if you have that capability. You will need to work up a design to coordinate the radio voice interface impedances and levels, and DC signaling with the channel unit requirements.

By the way, the FCC eliminated the 1st and 2nd class licenses. We all hold the General Class commercial license now.

Since you have dtmf capability, you could use that to switch the channel freq.

Good luck

Don