RT524 PRC77 GRC-160 Range info HELP

[ONTOS66]

1. To communicate with either of these radios you must have an amateur radio operator's license (as stated previously) and the ARRL web site is a good starting point. As to not finding anything on the web about a ham license? I did a google on ham radio license and found 26,400,000 listings. Which included the ARRL web site.
2. You "like the prc-77 for its portability" - you aren't going to like the range in that mode. With 1 - 3 watt approx output (according to the manual) your range is very limited.
3. Since you are talking vehicle mounted Your antenna of choice will be a vehicle mounted antenna, not the short or long antennas used with the PRC-77 as a manpack.
4. The RT-524 has a transmitting power of (approximately 35 watts on high power) according to the manual. I didn't dig for the amplifier output for the vehicle mounted prc-77 but my guess is it is in that range or slightly less.
5. How all that translates into range varies greatly. Terrain, weather, installation, flocks of geese, condition of your cables, and on and on and on. I've had days I could barely talk to my driver let alone another station any distance away.
6. Comparative cost of the two different installations can also be a factor. Do some shopping for all the components for the two types of radios for a vehicle installation. The manuals are available in the resources section of this site.
7. The frequency range that you can use as a licensed amateur radio operator are very limited with this equipment.
8. For an emergency communications setup I'd recommend looking in to ham gear that is compatible with local repeaters and other hams. The initial investment can be less and ranges can be much greater, even using portable equipment operating off of 12 volts in your vehicles.
9. The fun of green radios is that they are green radios and go with our green vehicles.

Good luck with your project.

 

[REGULATOR]

I'm still laughing at the "like the PRC for its portability " myself

seriously those things sucked when we had them on active duty, they woudl do in a pinch, we used to send the guy on guard duty out with them before they started buyin gthe nicer Brick handhelds..


Best idea is to install for looks and then use a good FRS/CB etc civilian product

If you wan to get licnesced there are so many good small 2m and 440 radios for Ham use. shoot a coat of OD green on the cases and install it somewhere out of sight

 

[ida34]

The AM-2060 amp does not boost the transmit output at all. Running the vehicle antenna will help over the small whip on the PRC77. There are amplifiers out there that you can get but the are separate from the AM-2060 unit that the PRC77 plugs into. I went with the PRC-25 and the AM-2060 vehicle mount. When I install it the radio will connect to my Vic-1 system. The PRC-25 is the predecessor of the PRC-77. I am not sure if the AM-2060 adds voltage to increase the output of the 77 or 25.

Chuck

 

[ONTOS66]

Regulator: It was an amazing upgrade when compared to the PRC-8/9/10 that we had to lug around before that - especially when you consider that it covered the frequencies that had previously required 3 radios. But, yes, it is a dog by today's standards.

I stand corrected on the AM-2060. It is an AUDIO AMPLIFIER and power supply. It does not increase the transmitting power, just makes it (relatively) easier to hear in the vehicle mounted mode.

My basic position still stands. For "cool" in the truck go green - for functional in time of emergency select the appropriate "modern" unit that fits your need and pocket book.

 

[Thomas P.]

The RT-524 will work best if used in conjunction with the R-442 Reciever Amplifier and two (2) Antenna whips mounted on your vehicle. The range will depend on the above mentioned variables, however given the same conditions, The RT-524 properly installed will outperform the PRC-77 manpack radio. However, one can use the appropraite mounting shelf and plug the PRC-77 into a vehicle base and transmit from her as well using the vehicles 24 Volts system, thus eleminating some variables....

I would stick with the RT-524 with a R-442 Amplifier.

P.S. might want to think about paying the $15 to take the 30 questions Amature Radio test ( Elementary students can pass the fisrt level..) to get your licence and thus avoid being fined or arested by the FCC.

 

[OPCOM]

Most of what I'd say on getting started and up and running has been said. I'll refocus on some details of which there are many that have not been mentioned. No one has mentioned the PRC-68. This is a hand-held radio using a 1-meter whip. Pls. google that as there are a couple versions. There is an older set, an RT-68. This is an all-tubes vehicular set. It is high-mailtenance, for collectors, and requires some technical knowledge to operate. Back to the -77:

In order of range on the PRC-77 using the 6M (50-54MHz) ham band:

3FT whip - worst. The radio wave is 6 meters long. A 1-meter antenna is only for compact use at short range.

10FT whip on the 77 - better. the best of the two radio-mounted antennas. But, it is not flexible and not fun to walk about with. Best to set the rig on the ground or a picnic tale if using that.

vehicle-mounted whip - best - Most (e.g. AS-1729) have a small switch on the underside and you will need to set that to the proper range (they are marked). Some newer ones (e.g. AT-3684) made for SINCGARS (which does frequency hopping) have a special network that broadbands the antenna, however, its performance (due to SWR up to 3:1) is a 11-25% less (power and sensitivity) than the kind with the switch when the switch is properly set. There is a cable for that purpose that runs between the AM-2060 an the vehicle antenna. The kind of antenna with the switch is prone to get water inside the tuning casing. It has a drain hole, be sure it is not clogged.

For mobile use, the PRC-77 or PRC-25 can use 12-15 volts from the vehicle. the -25 requires also a 1.5V supply for the tube it has as the transmit amplifier. The original military batteries have a special 'tap' for this. You can get a Ten-D-cell adapter that fits in the battery box and is compatible with the PRC-77 or -25 from PRC68.com. A set of D-cells can last a couple days of ON time, with limited transmit sessions.

The AM-2060 takes a 24V supply from a military vehicle and converts this to 15V and 1.5V for the PRC-25 and 15V for the PRC-77. plug and play. It also has an audio amplifier and a speaker so you do not have to hold the handset at all times or use a headset. It can be modded to be used on 12V by gutting the amp or modifying the amp, a job for an expert. The AM-2060 is designed to fit into the mount used for the RT524, so that is yet another item you will need.

For PRC-77 12V use, an after market amplified speaker has been developed by Steve Haney of Haney Electronics. It makes 8 watts or so of audio IIRC and has a power switch. It also has an internal power supply that makes the 1.5V for the PRC-25. It has a cable that plugs into the radio and supplies this power. It has another set of wire that is for the 12-15V vehicle hookup. I have 3 of these and love them. The speaker is made from a standard LS-type military speaker (appx. 4x4x3") and is as weatherproof as that is. Haney's amplified speaker is plenty loud and will get your attention, even for use on an ATV.

I have a PRC-77 mounted on its backpack, and this is mounted to the front cargo rack of my ATV and draws power from the ATV. I got 3KM distance in hilly wooded terrain with the 3FT whip. (The other end was a M35 with RT524 and vehicle mounted whip.) I would not consider backpacking a PRC-77 unless I absolutely had to. A Racal TRA-967 is much lighter if you must carry a military 6M backpack rig. I built an amplified speaker for my TRA-967 and its place is mounted on the backpack facing up towards my ear.

You will find the PRC-77 to sometimes unsquelch in the presence of alot of computer equipment. Consider it was designed when (common) computer clock speeds were nowher near 50MHz.

The RT524 requires 28VDC at several amps. (8A?) It weighs 60 LBS, less the required mount. The RT246 is similar except has in addition to the manual tuning, a set of ten pushbutton pre-sets. It requires an external LS-type speaker. It can use a remote control head to select the preset channels. Both are 35W on high, 8W on low. I have jacked one up to 60W, but that does not make much difference in range and is hard on the power supply and the transmit amplifier tube.

The PRC-77 can be given more transmit power by finding an old 50-100 watt illegal CB linear amp and modifying it to work at 50MHz. This is a job for an expert. Not all amps can be converted, because the transistors and ferrite transformer cores used in them do not all perform well at 50MHz. Do not expect 50-100 watts, you might get 10-20 if you are lucky but that is much better than 2. BTW 2 watts is the upper limit, most PRC-77 do about 1.5-1.8 watts. Be aware that using an external amp like this will suck the batteries dry quick if you are using D cells.

There is also a 50 watt SINCGARS amp floating around here and there that will take the 2 watts and do the right thing. It requires 28VDC to operate correctly. I was not successful in making it work cleanly on 12-14 volts (it generated harmonics/distorted RF signals and would interfere with other services). It also requires bandswitching (tuning signals) and some control signals which the -77 and -25 do not correctly provide. It also needs the 28V to operate the internal switching circuits. I admit I could have spent more time on this and possibly made it work but time is money.

There are smallish third party amps that will take the 2 watts there and boost to 30-50W, but these are costly ($200-300) and most require a control signal for switching to transmit mode. A RF-detection circuit could be easily made up and installed by an expert to remove that requirement. RM Italy is one maker.

The PRC-77, and all the radios mentioned here are wide band (except SINCGARS and to some degree the TRA-967), meaning their transmissions use up twice or so the typical 'channel' space used by modern 6-meter ham gear. This is not so much a big deal, but it means that any ham gear you hear will sound 'quiet' to you, and any ham gear you transmit to - you will sound quite 'loud' in their speaker. This has to do with the way FM works. Like another person said, you can turn down the deviation on the transmit side to narrow it up. However, there is no simple way to narrow up the receive side and improve that for your own reception.

All of these radios transmit, and need to receive, a 150Hz "subaudible" tone mixed withthe audio. This is a tone squelch. The RT-524 and RT-246 have a switch to use regular carrier squelch like any cheap commercial radio. The closest commercial tone to 150Hz is 151Hz. It is not always compatible, especially when trying to receive narrowband transmissions from commercial or ham radios.

One poster said the R-442 is an amplifier. This is a mistake. the R-442 is a receiver that us intended as an auxiliary receiver in a VRC-12 system. It is so that you can monitor two frequencies at once - one the tranceiver is on, and another that is for instance a special channel reserved for emergencies. In war, the scouts might be on one channel and the armor on another. Each has their 442 setup to monitor the other, but talk only among themselves on the 524. That sort of function.

I mentioned the VRC-12. This is a system, which may have several radios and an intercom. It can be quite elaborate. There is a TM or two on the subject in the manuals section. I have a modified version of this in my deuce. RT246, RT524, and a CB radio, all jacked into a VIC-4 intercom with three crew stations provids transmit, receive, and intercom between vehicle crew members. Blood sacrifice was required to perform this instalation. A fun-to-build custom interface was required to be built for the CB. There is room for one more tranceiver in the system. (some info here: Installing Aux. 24V and 12V Power and an AN/VIC-4 Intercom in an M35 Military Truck) More common is the VIC-1 intercom, whch accommodates two tranceivers and one receiver. That is what most people go with if doing a serious install.

For convenience I have attached the AS-3684/VRC ANTENNA SWR PLOT. This is a vehicle-mounted SINCGARS antenna. The AS-1729/VRC brochure (the band-switched type of vehicle antenna) is also attached. Also thrown in the AT-677/VRC ANTENNA SWR PLOT (this is for 2-meter and high band VHF use) and RENFROSNART DISPENSION FIELD CROSS SECTION FOR TYPE 4 CHILTZANGBRONE) which should be helpful for any type of plotting.

 

[cranetruck]

Interesting reading Patrick, you should write a book on it.