Kenwood: "Remoting" a TM-271
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mmckenna
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Not sure, I've never taken one apart.
You'd need to look at the schematics and see if it was easily done or not. If the control head is on a ribbon cable, then it's probably not too difficult.
A couple of things I'll point out, you do with it what you want...
-While amateur radio transmitters do not need type acceptance, the receivers do have a Part 15 certification. Making a major change like that to the radio would void it. Some wouldn't care, some might. Your radio, your money.
-If the radio is not designed to have a remote head, you might have to solve getting mic audio to the RF deck. It may require shielded cable for the mic circuit.
I know you don't want to buy a new radio, but it may be something to consider. A simple dual band with remote head might save you a lot of headaches. Use the TM-271 as a packet or base radio.
There are a number of single band two way radios that have remote heads, and some can be pretty inexpensive. I'm running several Motorola CDM-750's, 1250's and 1550's in mobile applications. Cheap on the used market, and can be set up as remote head.
I'm also running a number of Kenwood radios in remote head configuration for mobile installs.
These types of radios don't have a VFO function, but they do have enough memory space to add a lot of frequencies. I never had any issue adding all the 2 meter simplex frequencies as well as lots of repeaters.
You'd need to look at the schematics and see if it was easily done or not. If the control head is on a ribbon cable, then it's probably not too difficult.
A couple of things I'll point out, you do with it what you want...
-While amateur radio transmitters do not need type acceptance, the receivers do have a Part 15 certification. Making a major change like that to the radio would void it. Some wouldn't care, some might. Your radio, your money.
-If the radio is not designed to have a remote head, you might have to solve getting mic audio to the RF deck. It may require shielded cable for the mic circuit.
I know you don't want to buy a new radio, but it may be something to consider. A simple dual band with remote head might save you a lot of headaches. Use the TM-271 as a packet or base radio.
There are a number of single band two way radios that have remote heads, and some can be pretty inexpensive. I'm running several Motorola CDM-750's, 1250's and 1550's in mobile applications. Cheap on the used market, and can be set up as remote head.
I'm also running a number of Kenwood radios in remote head configuration for mobile installs.
These types of radios don't have a VFO function, but they do have enough memory space to add a lot of frequencies. I never had any issue adding all the 2 meter simplex frequencies as well as lots of repeaters.
I haven't looked at the TM-271 schematics or service manual. I will assume that there is a thin ribbon cable carrying signals between the RF deck and the control head. Extending that ribbon cable will be your biggest challenge as you would have to obtain the correct connectors and maintain proper shielding and impedance. That ribbon cable may be carrying MIC audio or there may be a separate cable.
As suggested, obtaining a single-band LMR radio that is designed with remote control heads in mind may be your best approach.
As suggested, obtaining a single-band LMR radio that is designed with remote control heads in mind may be your best approach.
I knew before I even asked that it would be more trouble than it's worth; I was curious if anyone had done it successfully. I use it for RX only and the sensitivity is outstanding. If I could find one with identical performance, then I would buy a mobile rig with a remote head.
mmckenna
I ♥ Ø
Most commercial radios have very good sensitivity. I'm running all commercial radios for my ham use, and I'll likely never go back to ham only radios. You'll find the performance is amazing. Trouble is, you need to be careful buying use gear. No telling what the previous owner has done to it. I'm fortunate to have a service monitor at work, so realigning used radios I buy is easy.
kayn1n32008
ØÆSØ
I will second or third using a LMR radio with a remote kit. TK7180, NX700 or CDM1250/1550 are my recommendations. All three have excellent sensitivity, but more importantly have far superior selectivity than the TM271.
The TK7180/NX700 i believe are close to the same size as the TM271, and have front firing speakers. They have amazing scan capabilities, and support dual priority, user selectable priority, single press add/delete, single press scan, 128 zones and 512 channels. They are truly superior to the TM271 in every way, except they don't have a VFO. The CDM series are much more limited in scan lists, and channels.
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I've modified multiple TM271A radios, never have done a remote head mod though.
They are very easy to get into and while the crux of doing a remote head mod would be extending the ribbon cable wouldn't be complex, but more of a PIA. I think the mod would best be done by using a braided cable (looks like maybe 24 conductor ?) to replace the ribbon cable.
The 271A does have superior rx specs.
For example, TK 7180
They are very easy to get into and while the crux of doing a remote head mod would be extending the ribbon cable wouldn't be complex, but more of a PIA. I think the mod would best be done by using a braided cable (looks like maybe 24 conductor ?) to replace the ribbon cable.
The 271A does have superior rx specs.
| Sensitivity (12dB SINAD) | Less than 0.18 μV (Narrow: less than 0.22 μV) |
For example, TK 7180
| Sensitivity (12dB SINAD) Wide Narrow | 0.25 µV 0.28 µV |
|---|
kayn1n32008
ØÆSØ
Sensitivity is only a small part of receiver performance.