Sensitivity better on ham radio

[mmckenna]

It's still fetching $300 on eBay now.

Sweet Jeebus. You can buy TK-7180s for way less than that, and they'll work just as good. Plus, they'll TX on the 2 meter band really well.
In fact, the last TK-7180 I purchased was $100 or so, and was an old BNSF radio, so it already had all the ARR radio frequencies loaded into it.

 

[dlwtrunked]

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?

I am amazed no one commenting saw errors in the above. The specification for the Pro-2046 says 0.7 microV which is 0.7 uV not 0.7 mV (millvolts). A second error is the IC-229 uses 800 mA not 800 mV. Note that the current drain is a function of the audio power output and that will be responsible for some of the power differences. As others have pointed out, the specifications of amateur equipment is only guaranteed for the amateur bands so you can make little conclusion from looking at the specifications from those there for other bands.

 

[natedawg1604]

I've heard great things about Kenwood radios, including several older models that are no longer made like some other folks are posting about. I often use an XPR 6550 to monitor conventional stuff and it works great for the railroads, great audio, great selectivity and intermod rejection.

 

[cellphone]

@thesavo, I use a TK-730 (older design of the TK-790) for scanning VHF including simplex fire frequencies in the Phoenix area. The radio is outstanding for VHF and there is no comparison with any scanner or ham radio that I have tried! I am very satisfied with both sensitivity and selectivity for this radio. The scan speed on the TK-730 is also very good compared to many ham radios that I have used.

 

[900mhz]

The difference between the amateur version and the commercial version of the Kenwood...VFO. Obviously not available on the commercial version, but is there for the amateur version. Sometimes, that comes in handy when searching for stuff quickly.

 

[mmckenna]

The difference between the amateur version and the commercial version of the Kenwood...VFO. Obviously not available on the commercial version, but is there for the amateur version. Sometimes, that comes in handy when searching for stuff quickly.

True, but the TK-7180 has space for 512 channels. Easy to add all the ARR channels in there and have lots of space left over.

 

[devicelab]

True, but the TK-7180 has space for 512 channels. Easy to add all the ARR channels in there and have lots of space left over.

And you can get them cheap... sometimes < $100

 

[mmckenna]

And you can get them cheap... sometimes < $100

Yep. I think mine was $100 or so.
It was an old BNSF radio, had all the ARR channels in it, as well as a few local agencies. I put it on the service monitor and it was still running within factory specs. I added a remote head kit and put it in my wife's truck (she's a ham also). It had plenty of room for adding all the standard simplex 2 meter frequencies, all the 2 meter repeaters in a 200 mile radius, at least, as well as weather channels. Still have a ton of room in the radio.

One other nice feature is that the display allows for longer alpha/numeric names for the channels that most ham radios offer.

 

[devicelab]

The TM-281A does have one terrible design flaw. You can only use 100 memories with alphanumerics or 200 memories with frequency information.

 

[thesavo]

Right now as eBay is my only source for now. As the radios will be used to receive OTA for Broadcastify, the requirements are the following:

- Would prefer 4 simialr radios as I have to procure programming cables and software (Ham radios exempt)
- one channel or two channels at the most, channel capacity and scanning speed is not an issue.
- RX only so - blown finals or amp circuits and high power out, not needed.
- All the VHF I am feeding have no PL tone (for now)
- mic Not needed
- Preferable to have a complete unit and non remote mountable. Built-in speaker in basic controller for local monitor if Fixed audio out is available.



TM-241a- $30 (auction) pair of units for parts as TX bad on one,. #2 has bad display.
$32(auction)-$159 sold as excellent condition
TM-261a - $44(auction)-384 - 3 units each listed as good condition
TM-281a - $200 - 1 unit from china

TK-7180 - None for sale
TK-7160 - $80~$175 - 3-4 units available


TK-730 - $75-200 Radio only 4-5 units available
The split is 150MHz - 174MHz Type F1 and 136MHz-156MHz F2
I would need Type F1 for Rail radios and F2 For Ham. I would like to stay with in the given splits
TK-730 KCH-3- $10 ea in a lot of 4. - Presumably this would work with either type of 730

TK-790 seems to have the best availability, sold as remote mount with the KCH-11 control head
Tk-790 - $40 - 1 headless unit or 2 units sold for parts
$45-60 head units 6 available
$80 - complete unit modified for modem use
$85 - headless
$65 - 3 headless
$175 - 6 complete units with KCH5 heads - sold as-is

Thoughts?

Eventually I need a good mobile ham radio but for now I want the best receivers for my Broadcastify feeds.

 

[mmckenna]

Cheap and easy would be an Icom F-320S. 4 channel, small basic radio. Will do narrow band.
I've had some of these in use for 20+ years now.
If you don't need a mic, there is at least one on e-Bay for $35.00. Standard amateur radio T-power connector. Easy to program.

 

[thesavo]

Cheap and easy would be an Icom F-320S. 4 channel, small basic radio. Will do narrow band.
I've had some of these in use for 20+ years now.
If you don't need a mic, there is at least one on e-Bay for $35.00. Standard amateur radio T-power connector. Easy to program.

Neat. I'll check. Looks like it starts at 146mhz too.

 

[wwhitby]

The difference between the amateur version and the commercial version of the Kenwood...VFO. Obviously not available on the commercial version, but is there for the amateur version. Sometimes, that comes in handy when searching for stuff quickly.

FWIW, I've never found the lack of a VFO to be a hindrance. Once I program frequencies in my ham HTs and mobiles, I've found that I rarely add anything new or need to use the VFO. Of course, like most things in life, YMMV.

Also, my son has a TM-281a. Outstanding radio. He had me test it out for him, and I did program in local railroad frequencies and the reception was pretty impressive.

 

[thesavo]

I am curious about the output of the Icom F320. I found in the user manual and service manual there is an optional output cable
OPT-617
Pin out below
1. LCD backlit cont. IN
2. AF OUT
3. Det. AF OUT
4. Mod. IN
5. PTT control IN
6. Horn drive cont. OUT
7. AF GND
8. Det. AF GND
9. Mod. GND

I have not found what these abbreviations mean. Are any of them fixed received audio out isolated from the volume and amp? I am leaning to this PAAF output on the optional cable.


However it would seem that is for Public Address audio not RX audio. Based on this pinout from the service manual, is it pins 3 and 8 for the DISC signal?
It;s not a deal breaker if it can't be done with this unit. I just wanted to have the option for local monitor and not have it effect the feed.

 

[mmckenna]

Discriminator output is the flat audio feed you are looking for. So, Yes, pins 3 and 8.

 

[thesavo]

Wonderful. I'll grab that radio and a cable from ebay. I'll check AME radio for the software.

 

[thesavo]

Sold! $40 for the radio, $132 for the software and cable from ameradio.

 

[devicelab]

Isn't RR activity up in the NE on NXDN now? It's not over here -- still fully analog -- but I thought the midwest and NE was almost all NXDN.

 

[thesavo]

Isn't RR activity up in the NE on NXDN now? It's not over here -- still fully analog -- but I thought the midwest and NE was almost all NXDN.

Pam am rail here is still analog FM.

 

[kruser]

Isn't RR activity up in the NE on NXDN now? It's not over here -- still fully analog -- but I thought the midwest and NE was almost all NXDN.

Very little NXDN heard here and what was heard was just used for things like yard operations but road channels will be analog and will likely stay analog until ALL railraods are ready to switch.
It's very rare I hear a NXDN signal around St Louis or from the huge rail terminals just across the river in Illinois. Still too many different users involved for a blanket switch to NXDN. All the users licensed in this area are also still modifying their FCC licenses to add NXDN emission types but those modifications are far from complete. I think it will be quite a while before we see NXDN use on the road channels on any line that may share trackage rights with another operator.