Motorola radio question

[SouthernRailFan]

I purchased a motorola handheld 2 way for receive only to monitor the railroad AAR channels. My question is do 2 way radios have the same signal range as scanners or are they less, and I also monitor the FEC and they only pick up within a certain distance like its on a repeater but i pick them up just fine from far distances on my old base scanner. I know CSX dont use repeaters i dont think, is that why u can hear them for good distances, thanks for any info.

[Pj]

There is no direct answer, but I will offer this....

Ensure you have the correct band antenna on the radio. Motorola antennas are offered in narrow ranges and they do have a wideband antenna available. If you have a 150-156 antenna, 160ish can be severely attenuated (been there, done that).

Without knowing the model or condition of the radio you have, it may need to go to the local service shop and have it aligned on a service monitor for peak performance.

Railroad engine radios are 45 watt radios based on a Motorola or Kenwood radio. Between their upkeep, antenna location and antenna used, anything can happen. Base/tower radios can be anywhere from 25 to 100+ watts.

In short, it can be anything. Typically commerial radios will out perform scanners, but there are many varibles that can come into play.

[Bill_G]

+1

There are some great scanners out there, some crummy portables, and vice versa.

[sataraid1]

There is SO much variation between locomotive cab radios these days they're almost useless as a benchmark for reception. One train can barely be heard 5 miles away, the next can be heard 25 miles on either side of your location.

With that said, I recently acquired a P1225 for railroad monitoring, and I love it. It picks up much better than the Yaesu HT I'd been using, and it wasn't exactly a slouch, either.

The first thing I did when I got it, however, was buy a new OEM antenna in the correct range. As stated above, there are lots of opportunities for a mismatch, and also a lot of knockoff crap that looks identical but isn't.

Even if the range could be considered equal, something that's impressed me about the P1225 is that it still picks up well when in a back pocket or tote bag. If I slipped my Yaesu into my back pocket while monitoring, its range would drop off severely. It doesn't seem to faze the P1225 at all.

[escomm]

All other things being equal, a radio will work better for reception than a scanner. The front end is narrower and more selective. A scanner, by definition, has a front end so wide a mack truck could drive through.

[SouthernRailFan]

What is a good antenna for a motorola for the railroad frequencies. The one that came with it is a Heliflex rated for 136-174MHZ. Seems to do fine but its only 6 inches, wondering if theirs something a bit longer that would increase the signal and reception.

[Pj]

We will see if this image will work (stolen via Google via Photobucket from eBay)

This is the best Motorola antenna you can get, part number 8505518V01 $20


Prob the same one you have. Other than that, you could order the 8505644V02 150-160 or 8505644V03 which is 162-174.



Beyond that most antennas will require some sort of adapter on the radio which may induce loss and cause an additional weak/break point. My flow chart would be:

-> Change antenna
-> Have radio serviced
-> Your just in "that" area that just sucks for reception

Also if they have gone narrowband, the voice/signal may be a little different. Some claim lesser distance for the same power, some claim softer voices, or a combination of the two. Some notice no difference. If they are using the "0" channels such as 036 vs 36, those are the narrowbanded AAR channels. You will almost never hear this on the radio, and the information would be in the current timetable, system general orders etc.

You have not stated what model Motorola you are using.

[sataraid1]

I've been using the NAD6502AR VHF Heliflex, 146-174 MHz, which looks just like the second picture above. I'd be interested in knowing what radio the original poster is using as well.

[Will]

The 6" heliflex antennas do NOT cover that wide of a band. In your case the range would be 151 to 162 or 162 to 174 mHz.

There are aftermarket helical antennas that can be cut to a specific frequency but they only cover a small segment of the VHF Band. Most likely only + or - 3 mHz in the VHF Band.

[SouthernRailFan]

Yeah ive got a antenna on its way for the specific 151-161 mhz that i need. Hope it helps out some.

[Pj]

What model radio are you using?

[SouthernRailFan]

Motorola CP185. It picks up good but eventually ill upgrade to something a little better but it will due for now.

[sataraid1]

The 6" heliflex antennas do NOT cover that wide of a band. In your case the range would be 151 to 162 or 162 to 174 mHz.

There are aftermarket helical antennas that can be cut to a specific frequency but they only cover a small segment of the VHF Band. Most likely only + or - 3 mHz in the VHF Band.

I'm sure you're sure, but ... are you sure?

All the Moto documentation I have on the P1225 shows the NAD6502AR as "146-174", with no distinction between the two ranges. MOL lists it as "WIDEBAND VHF ANTENNA". Even the original Moto packaging on my antenna failed to state a range.

If so, how do you identify the range, and if there are no differences in part numbers, how do you know which one you're getting?

[RadioSouth]

The NAD6502AR is 146-174 and has a black dot on the threaded base to distinguish it from the 136-162 which has a yellow dot on the base, don't recall the part # but it is different from the 6502. So if you're using the 6502 for R/R that would be your best choice from Motorola, the only other VHF antenna's they sell for these are shortened helicals which don't work as well as the longer type.

[NSPD]

Many railroads are using these:

http://www.tessco.com/products/displayP ... ventPage=1

I have used one myself and it was a pretty good antenna, centered at 160mhz.

[Bill_G]

I've seen those. the threads fit Icom and Mot.