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-   -   Kenwood TM-281A (http://forums.radioreference.com/amateur-radio-equipment/220926-kenwood-tm-281a.html)

nickcarr 09-08-2011 4:27 PM

Kenwood TM-281A
 
I just placed my order at HRO as these just came in stock.

Kenwood TM-281A Mobile Transceiver TM281

There's no brochure or manual on the Kenwood site but I did manage to find the manual online:

http://images.kenwood.eu/files/prod/...M2_English.pdf

I'll post a mini-review when it arrives next week.

W9BU 09-08-2011 4:57 PM

While this radio may be "narrow-band capable", according to the manual, this radio does not have 7.5 kHz tuning steps. However, it does have 2.5 kHz steps, so you should be able to listen to narrow band VHF signals on the correct frequency.

nickcarr 09-08-2011 5:49 PM

I'm not sure I understand your comment. If the radio supports either 2.5 or 3.125 steps (or in this case 6.25) then it's narrowband compliant.

You do not "need" true 7.5 steps if you already have 2.5 steps.

W9BU 09-08-2011 9:43 PM

Narrowband and VFO step size are not necessarily the same thing. Narrowband, in the context of VHF land mobile radio, requires a receiver and transmitter designed for 11kHz bandwidth frequency modulated voice (emission designator 11K0F3E) instead of 16kHz (16K0F3E) or 20kHz (20K0F3E).
The narrowband channel spacing in the VHF land mobile band is 7.5kHz instead of 15kHz like we've had in the recent past.

So, your statement that 2.5 or 3.125kHz steps makes the radio narrowband compliant isn't exactly true since the step size does not define the bandwidth of the receiver or transmitter.

However, your statement that 7.5kHz steps are not required if you have 2.5kHz steps is true.

ST-Bob 09-09-2011 10:20 AM

According to the factory rep I talked to at HRO in Salem NH a couple weeks ago, the TM-281A is a replacement for the TM-271A and is nearly identical except for the following 2 or 3 notable differences:

1. The display backlight is amber to match the microphone backlight (271A is green)

2. The pads on the board for digital data connections have been removed (the TM-271 can have the packet data cable added)

3. The front panel buttons are more streamlined and the function button is different from the others now.

It's basically an updated, slightly cheaper to manufacture TM-271A - a really rugged high-powered (25/60W) 2m only radio. You might be better off to find closeout pricing on a TM-271 in my opinion. I love mine.

nickcarr 09-12-2011 6:44 PM

My first Kenwood...
 
Received the TM-281a today. So far so good. The audio is exceptional compared to my V8000. I thought the Icom had pretty good audio but the Kenwood radio wins out. The front-firing speaker is rated at 5w and puts out extremely loud but clear, crisp audio. The internal design looks to have changed somewhat compared to the TM-271a. The PA section looks to have been upgraded. Overall it's a very clean design. The entire base of the radio is the usual thick die-cast metal and acts as the radio's heat sink. There is no fan. Power output is either 25 or 65 watts.

I don't own a TM-271 but this model only uses 2 screws to remove the top cover -- and the top cover is a hard plastic. It snaps tightly over the mounting screw holes and feels quite solid. (I read that the TM-271 uses 8 screws to remove the cover.)

The microphone feels great in the hand. It's a little bulkier compared to the Icom microphone but it has a quality feel -- and the PTT switch is firm and has a solid "click" response. I've heard audio reports from other Kenwood mobile users and they sound amazing. So I'm hoping this model also has that great Kenwood audio output.

Probably the best feature is the simplicity of the radio menu system. It's 100x easier to use than the Icom V8000. It's very intuitive and doesn't require more than 15 minutes of learning.

I have received good audio reports so it's working just fine. Here's an internal photo of the TM-281a. (Send a PM if you'd like a full-size image.)

http://home.comcast.net/~cnick6/tm281a.jpg

KE4NYV 09-15-2011 10:23 AM

Quote:

Originally Posted by ST-Bob (Post 1608719)
2. The pads on the board for digital data connections have been removed (the TM-271 can have the packet data cable added)

Oh man, that's a really dissapointing thing to read! That is why I loved the 271 so much. It was so easy to add packet connection and it worked really well!

KV4BL 09-15-2011 11:31 PM

Kenwood TM-281A
 
Quote:

Originally Posted by ST-Bob (Post 1608719)
According to the factory rep I talked to at HRO in Salem NH a couple weeks ago, the TM-281A is a replacement for the TM-271A and is nearly identical except for the following 2 or 3 notable differences:

1. The display backlight is amber to match the microphone backlight (271A is green)

2. The pads on the board for digital data connections have been removed (the TM-271 can have the packet data cable added)

3. The front panel buttons are more streamlined and the function button is different from the others now.

It's basically an updated, slightly cheaper to manufacture TM-271A - a really rugged high-powered (25/60W) 2m only radio. You might be better off to find closeout pricing on a TM-271 in my opinion. I love mine.



Thank You for clearing that up, ST-Bob! I had been wondering what the difference was since I saw the ad on the back of this month's QST. It sounds like they could and should have just left well enough alone. I would have thought a newer version would have at least warranted a full 200 alpha-numeric channels, a five-watt option, and maybe a fan, at the very least. I wonder if the excellent WX Alert system is still intact.

73,

Ray

ST-Bob 09-16-2011 7:13 AM

Supposedly the weather alert is still there and may actually be improved a bit. One thing I don't like about the TM-271's weather alert is that you cannot hear the weather audio on the WX channel you've entered once you turn on the WX Alert function. It mutes the audio until the 1000 Hz tone is detected. However, all you have to do is program a weather frequency into another of your 100 (or 200) channels and set SKIP on for that channel so it won't automatically stop there when scanning.

mrweather 09-16-2011 6:54 PM

Quote:

Originally Posted by KV4BL (Post 1612632)
and maybe a fan, at the very least.

On the contrary I'm glad they didn't. One less thing to fail. None of my commercial Kenwood TK-690, 790 and 890 have a fan. They use the radio chassis as a heatsink.

KE4RWS 09-29-2011 4:51 PM

271 or 281
 
I was wondering what the difference was between the 271 and 281. I guess I'm surprised Kenwood would change out and entire model for the few small changes they made. But maybe there's more to it than what I think.

I packed my TM-271 away in the box along with all my other Kenwood & Motorola radio gear and completely abandoned amateur radio operation three months ago because of three or four idiots in my area who treat other people like garbage, lie/boast about how much money they claim to earn, and completely trash other amateur operators they don't "like". I doubt I will ever get back on the air again but even if I did I wouldn't have any reason to trade-up my 271 for an amber backlight and slightly different buttons :lol:

Prior to my TM-271a I owned three Yaesu FT-2600R 2-meter mobile's, which were nearly identical to the 271, and were used for packet and APRS stations. Although I really loved the 2600's, they tended to lose their memory occasionally under certain conditions, which was a known issue for that particular model. I liked the idea of the 271 having the ability to add a data cable interface in the event I wanted to use my radio for packet (which I never did because I was still using an old TM-241 for that purpose - but I *could* if desired).

Like the 271, the 281 does look like it will be good model though :o

matt25 10-07-2011 10:52 PM

just wondering if anyone knows how to cap/mod the tm-281 ?

nickcarr 10-09-2011 1:25 AM

I think it's R768 but I haven't tried it yet.

matt25 10-09-2011 8:13 AM

so maybe i need to try this then because without this mod its just sitting in my truck not being used lol!

matt25 10-09-2011 8:23 AM

so just clip out the chip thats r768?

spd640 10-09-2011 4:59 PM

I bought a 281 but did not realize until it arrived it was a cheap made in China product

nickcarr 10-09-2011 5:12 PM

Quote:

Originally Posted by spd640 (Post 1625571)
I bought a 281 but did not realize until it arrived it was a cheap made in China product

Feel free to donate it to me. I'll test the modification. :twisted:

matt25 10-09-2011 7:08 PM

the mod works i tried it today i took out r768

nickcarr 10-10-2011 1:00 PM

Quote:

Originally Posted by matt25 (Post 1625645)
the mod works i tried it today i took out r768

Yeah it's just a resistor.

Very cool to know Matt. Thanks for testing it. I just guessed by looking at the schematics. The resistor is using the same control line as the 271A.

bertedmund67 10-11-2011 7:58 PM

Quote:

Originally Posted by matt25 (Post 1625645)
the mod works i tried it today i took out r768

Hello matt25,
Is this mod really work on the kenwood tm-281a? Do I need to reset the radio or it does automatically? Thank you.

Bert


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