Sensitivity better on ham radio

[thesavo]

I am sure I am I reading this wrong.
Below are the spec pages for the following radios showing their sensitivity and power draw.

• icom ic-229 Ham radio
  • < 0.16 uV
  • 800 mV
• kenwood tk-790 public service
  • .0.25 uV
  • 2200 mA
• Radio Pro-2046 scanner
  • 0.7 mV
  • 460 mA

I want to replace the scanner with one of these other radios given their availability. My first plan is for the local rail road as picking up locomotives is difficult right now. I also want better reception on 2 meter and would put the next available radio on those.
I am moving my antennas up to the attic, but I also wanted something better than a scanner for my feeds.

Does it make sense that a ham radio has better sensitivity than a public service radio?

 

[kruser]

Pay attention to the footnote for the Icom and most other amateur radios that have wide band receive.
The wide receive range is more of a perk but the specs are not guaranteed outside the 2 meter band. This would include the sensitivity spec you are looking at.
Sensitivity could start dropping off quickly as you tune above 148 MHz in this model. They don't test it so the specs you highlighted may not be correct.

Finding someone else that uses that model for rail scanning would probably give you a better picture as to how well it works at 160-161 MHz.

 

[thesavo]

That is a very good point that I didn't think of. Well I can atleast get this icom radio for picking up the 2 meter repeater feed and test it on rail. If it has better receive for rail, then I will try to obtain more. If not, ill give the tk-790 a shot.
Thanks for the help.

 

[jhooten]

While two way radios, amateur or commercial, may have a scan function they make lousy scanners for general monitoring. The scan rate is usually slower. Temporary nuisance channel lock out is not a simple button push. Less memory channels. Organizing into scan lists and banks is limited. Bump a button they stop scanning. The extra sensitivity leaves them vulnerable to overload and de-sense. To name a few. And with the commercial radios you will need the computer, cable, and software to make changes to the programming which makes on the fly updates a PITA.

Knowing this and not getting your expectations to high they can work. I kept my older analog scanners for scanning the amateur repeaters instead of scanning on the transceiver because of this.

 

[mmckenna]

Selectivity is a nice thing to have, also. It's not hard to make a super sensitive receiver with poor selectivity.
If you are going to be using this for rail road listening, you may have issues with strong nearby signals.

And don't forget the importance of your antenna...

 

[iMONITOR]

Dynamic range is also important.

 

[wwhitby]

FWIW, I have occasionally used the IC-229 that I have in my Jeep to monitor the railroads. It worked fine.

 

[thesavo]

As they provide feeds to broadcastify the only scanning the rail is doing is dispatch and lcoco near me.

2 meter is the same. It will be on a static frequency for my broadcastify feeds.

 

[Tim-B]

I use an Icom IC-V86 for railroad monitoring and it works great. It is a handheld ham radio but it receives on 136-174. It has better sensitivity than any of the 15 or so scanners I own. Since it has a BNC connector I use it in the car with the DPD Productions mobile 5/8 wave traintenna and with this setup I get much better range than just a handheld with its own antenna inside the car. When indoors and sitting side by side on the shelf with a scanner and a Smiley Antenna slim duck tuned to 160 MHz on each radio the V-86 will receive weaker signals that do not break squelch on the scanner. And the V-86 has one big advantage over a scanner - it is LOUD. When standing on the platform at the local Amtrak station with a 4400 HP diesel running right next to you and people coming and going and road traffic passing I cannot hear the speaker on a scanner at all if it is on my belt. The V-86 had 1500 mW audio which is about 4 times as loud as most scanners. I can hear the V-86 in the car with the windows down and the road noise no problem.
I have not had any intermod problems yet with the sensitive receiver.

 

[KB2GOM]

I use an Icom IC-V86 for railroad monitoring and it works great. It is a handheld ham radio but it receives on 136-174. It has better sensitivity than any of the 15 or so scanners I own. Since it has a BNC connector I use it in the car with the DPD Productions mobile 5/8 wave traintenna and with this setup I get much better range than just a handheld with its own antenna inside the car. When indoors and sitting side by side on the shelf with a scanner and a Smiley Antenna slim duck tuned to 160 MHz on each radio the V-86 will receive weaker signals that do not break squelch on the scanner. And the V-86 has one big advantage over a scanner - it is LOUD. When standing on the platform at the local Amtrak station with a 4400 HP diesel running right next to you and people coming and going and road traffic passing I cannot hear the speaker on a scanner at all if it is on my belt. The V-86 had 1500 mW audio which is about 4 times as loud as most scanners. I can hear the V-86 in the car with the windows down and the road noise no problem.
I have not had any intermod problems yet with the sensitive receiver.

I did not know my IC-V86 would do that. It's NOAA weather radio reception is pretty good too.

 

[Tim-B]

Yep, just program the RR frequencies into the memory channels at it will do receive only. Since I am not a ham then the RR frequencies are the only ones I have in mine. I enter the frequencies so that the memory channels correspond to the AAR channel numbers. Since its scan speed is only about 10 channels per second I only have the half dozen or so local frequencies set to scan but they are all in there. The rest are just set to skip. You can directly access a given channel by just keying in the three digit channel number when you are on the MR mode on the display. You can also set channels to either scan or skip on the fly when you are in different areas.

 

[RRR]

When standing on the platform at the local Amtrak station with a 4400 HP diesel running right next to you and people coming and going and road traffic passing I cannot hear the speaker on a scanner at all if it is on my belt.

Why would you think you could with any radio? That's one of the reasons for a shoulder mike.

 

[Tim-B]

I can hear the V-86 just fine in that environment.

 

[jtwalker]

I can hear the V-86 just fine in that environment.

Well, then you are probably annoying all those people around you that are coming and going.

 

[Tim-B]

No, they are by the passenger cars. I am by the locomotives.

 

[cbehr91]

All modern radios have about the same sensitivity. Intermod, image, and adjacent channel rejection are more pertinent receiver specs that will determine which is "best". Generally, an LMR radio will have better intermod rejection than a ham radio, and a ham radio will have better filtering than a scanner.

A radio on a test bench could measure .1uV of sensitivity on a test bench, but hooked up to an antenna of any sort get blitzed by all kinds of outside signals. QST magazine does advanced receiver testing on almost all commonly available amateur radios.

 

[JoshuaHufford]

While I've not used any of the radios you mentioned, I have used a Motorola M1225 Radius and CDM1550 for monitoring the railroad channels, along with a Uniden BC125AT. While the Motorola Radios I've found do have better sensitivity than the Uniden, it isn't by much. However the selectivity is MUCH better, I can only think of one time I had a problem with intermod with one of the Motorola radios, and that was when I was parked right next to a transmitter for Public Safety.

They also have much better audio quality than a handheld scanner. I have an external speaker I sometimes put in the car when on railfan trips, I can crank up the volume on that with the windows down and hear it quite a ways away.

 

[devicelab]

I guess it has gone discontinued now but you can probably find a used Kenwood TM-281A transceiver: Kenwood TM-281A Mobile Transceiver TM281

Excellent radio with very sensitive receiver.

Found a decent video of this radio:

 

[900mhz]

I guess it has gone discontinued now but you can probably find a used Kenwood TM-281A transceiver: Kenwood TM-281A Mobile Transceiver TM281

Excellent radio with very sensitive receiver.

Found a decent video of this radio:

I have two of these 281's. Great radio. Excellent sensitivity and selectivity in and out of band. Plus it can be set up with software. Can't beat this rig.

 

[thesavo]

I have been watching the 281. It's still fetching $300 on eBay now. If anyone one has one with a broken final amp they would be willing to sell, I'd be happy to buy. Since it will be receiving only.