VIC 12 pro's, cons

[truck1]

VRC 12 pro's, cons

I am installing a remotely controlled RT-246 in the bed of my M-1028 pickup. What are the advantages or disadvantages of adding a RT -442 receiver . Will I gain more channels or be able to monitor other stations while transmitting? Or should I put the extra money towards a commercial ham radio which I want in addition to the green system.Thanks.

 

[wsucougarx]

You will be able to monitor another channel while transmitting on another. It's actually only an R-442 (R= receives only). For looks and authenticity an R-442 looks pretty good next to a RT-246. I have that setup in my m109A3 truck. Though they both work great, I'd like to add a commercial HAM radio someday.
As far as cons, there are several. But we don't buy green radios for the cons.

 

[Wile E. Coyote]

They do indeed look cool and, as mentioned, you can listen to something else while transmitting/ receiving on the RT-524 or 246. Just *don't* transmit on the RT-524/246 and have your R-442 tuned to the same frequency in the same vehicle. Plus, if your RT-524/246 ever develops a receiver fault, the R-442 contains the same receiver modules you can borrow to help troubleshoot your big set.

 

[truck1]

I had planned to test my setup just as you described. I purchased a sweet AN/VRC 12 set up from Private Jarhead.Great guy and radios are CLEAN! Picked them up at Tower Park. Almost ready to power up.Pics of installed rig to follow.What are the reasons to not transmit between a RT-246 and an Aux.R-442 in the same vehicle? I don't want to damage a nice set through ignorance. Also will a C-2298 work as a remote audio box with out a VIC 1 box? I don't need an intercom system in the 1028. The TM shows a C-2299 retrans box in the remote only audio role. I have a C-2298. Thanks for the heads up.

 

[coop]

In the AN/VRC-12 Series, I think the RT-524 + the R-442 with Aux Receiver Loudspeaker is the AN/VRC-47 set. One of the advantages of this set you can operate Duplex with another like station. Station 1 transmits on station 2's receiver frequency and station 2 transmits on station 1's receiver frequency setting. Example would be station 1 transmits on 51.0 MC and receives on 52.0 MC, station 2 transmits on 52.0 MC and receives on 51.0 MC. Hope this helps.

coop

 

[Wile E. Coyote]

The setup with the R-442 also lets you work with repeaters, which of course receive on one frequency and transmit on another ("input" and "output" frequencies.) The way you usually set it up is have a bunch of vehicles transmitting on 52.0 and receiving on 54.0 - then you have a repeater on a mountaintop with the reverse setup: transmitting on 54.0 and receiving on 52.0 Mhz. That way any vehicle in the fleet transmits - it goes to the repeater - and the repeater rebroadcasts it from the top of the mountain to all the other vehicles. This is used primarily to increase range/coverage, as VHF signals for the most part are line-of-sight - so if there's intervening terrain (mountains, forests and such) you have a problem that the mountaintop repeater helps solve.

Sorry if that's all painfully obvious.

 

[tennmogger]

The problem with receiving on one receiver while transmitting in a band on another transmitter-receiver is that the receiver front end will be overloaded even if it's on a different frequency. That's why the receiver in the transmitter-receiver is turned off for transmit. For example, a transmitter anywhere on 6 meters will probably make a receiver like the '442 completely useless to hear any weak signals in-band and for many MHz up and down.

The R-422 would typically be used to monitor a different frequency from the receiver in the transmitter-receiver, but not during transmit.

Ham and other repeaters use very high selectivity devices to keep the transmitter energy out of the (off-frequency) receiver. Those are not part of the receivers or transmitters. The military knew that, and provided a diplexer to isolate the receiver and transmitter, typically a CU-2194 or similar. This device would even let the separate receiver and the transmitter use the same antenna (but having separate antennas on the same vehicle is darned near the same). So, get a diplexer and you can receive on the R-442 all the time as long as the second receive frequency is outside the 3 MHz difference specified in the CU-2194 specs (that is, even the diplexer can't filter out the transmitter within 3 MHz).

That said, if the Tx and Rx frequencies are separated by many MHz, then it'll probably work for stronger received signals.

Bob WB4ETT

 

[truck1]

Thanks for all the technical replies. I need to understand this setup now that it is installed in my 1028. Install went well with the usual search for the correct cables and mounts. Went with the MX 7777b. I do like the added surge protection. Question though ,can I leave the RT246 and the R442 powered on at the units themselves and kill power at the MX7777 without any adverse effects? My transceiver is controlled remotely from the cab so it can be powered off from the C2742. Also want to give a plug to Private Jarhead for all the help and excellent hardware, mostly NOS! I highly recommend him for your radio equipment needs. And his prices are very fair with great service warranties and all radios thoroughly tested. Here are some pics. Sorry some of these pics rotated and I can't figure out how to fix them.

 

[Welder Sam]

Nice rig