Radios & Power output

[Christiaan Adams]

Hi all, 

During the on-air conversation after the net this evening, someone asked for more information on the Kenwood TK-880 radios and their use for GMRS.  The document linked below has most of the details. Please let me know if you have other questions or want a copy of the programming software and my latest programming files. 

Buying & Programming a Kenwood TK-880 for GMRS

Also, regarding the BTech GMRS-v1, and whether its power output is 2W or 5W.  Here is the manual I was referencing (on the BTech website), and on p72 it says: 

RF power L/H: .5/2

Note the decimal point before the "5", meaning it's: Low:0.5W, High:2W

Can the person who saw it listed as 5W share a link to the source?  Would be great to know if this is actually a 5W radio.  

Thanks! -Chris KJ6WEG / WQPD858

[Michael Gold]

Chris, thanks for that. I see one of the 25W versions on Ebay now, with the FCC ID ending in 10 indicating legacy Part 95 compatibility, and the designation v2 apparently indicating the Windows-compatible firmware. I'd looked at these labels recently for the ID and not noticed the version number.

Now about the 25W (TK-880) and 40W (TK-880H) versions. I see in the service manual 2 lines that describe low power, one indicating adjustments for 5W and the other for 10W. Does that mean TK-880H outputs 40W high and 10W low, and TK-880 outputs 25W high and 5W low? Or can a technician adjust both models to output 5W in the low setting? Per your link, service manual here, I'm referring to p55

http://www.repeater-builder.com/kenwood/pdfs/tk-880h-svc-man.pdf

Kenwood's spec sheet notes a difference in certificates between TK-880 and TK-880H. What does it mean, and in practice does it mean anything?

Again per your link https://criticalradio.com/Kenwood%20Spec%20Sheets/Data%20Sheets/TK780h_880h_ver2_k.pdf

TK-880 FCC parts 22, 74m 90, 95 (at the time)

TK-880H FCC parts 22, 74m 90, 90.210, 95 (at the time)

In another document, TK-880H also has a 90.203 (g) designation, I think indicating some technician-modifiable features that are not user-modifiable. But maybe TK-880 has those features as well?

And now a word from the FCC

"Several commenters are concerned that the proposal to prohibit combination radios would prevent GMRS licensees from using surplus Part 90 equipment in GMRS.  See, e.g., Comments of Jerry Scott Parham at 3.  This is not our intent."

http://transition.fcc.gov/Daily_Releases/Daily_Business/2017/db0522/FCC-17-57A1.pdf

I suppose none of the older units can hold to the .5W ERP limit for the 467 interstitials (same center frequencies as FRS 8-14), or anyway not without unusual hardware modifications.

-MG WRJB283

[Richard Perlman]

Michael:

For more information on Part90 radios in GMRS, check out this forum post and a couple following it.

Richard

On 26 Aug 2020, at 12:51, Michael Gold <contac...@gmail.com> wrote:



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[Doug M]

The BTECH V1 outputs 0.5/2W as noted from both the Web site and its User Manual and on my SWR meter.

I thought I heard 5W in relation to the Wouxun (KG-805G), which would be correct. The Wouxun outputs 0.5/5W.

-Doug

WQOY819 / KI6DOG

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 Doug Mosher

   

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[Christiaan Adams]

Hi Michael, about the Kenwoods... 

I don't know for sure about the power settings, but I assumed the TK-880 is High:25W Low:~5W, and the TK-880H is High: 45W, Low: 10W.  

As for the certification differences between the 880 and 880H, Looks like the H model adds 90.210. I don't know what that's for, and don't think it's relevant for GMRS, so I wouldn't worry about it.  

Best Regards, -Chris

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[jayrfenton]

Hi Chris. Your correct on the b-tech v1 on-site manual and their advertised specifications. I sent b-tech an e-mail asking if they had reduced the tx output. I'm withholding my recommendation on this radio if they have in fact downgraded this radio. 

Sent from Samsung tablet

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[Christiaan Adams]

Thanks Jay, that's great, let us know what you hear from BTech.  Were you the person yesterday evening, who said they had tested a GMRS-V1 and seen 5W output? Sorry I forgot the name/callsign from the discussion last night.  Cheers, -Chris

[Michael Gold]

There is some mystery about the Btech and there may have been some change. I say this because the table that describes radios confirmed to work with BeCERTAINN has a note indicating GMRS-V1 is "kneecapped" version of Btech UV-82. Btech describes UV-82 as discontinued, but as having had 1W/5W power stages. Dirt cheap knockoffs are available but the 1 W power stage does not comply with the 0.5 W limit on the 467 interstitial channels so I would not recommend to neighbors. (I see lots of radios out there that are marketed as UV-82, some as Baofeng UV-82 which I doubt are real. The variants might have different power specs than the discontinued Btech.)

Considering that available Btech GMRS-V1 units are specified as 0.5W/2W, the Wouxun KG-805G specifications have the advantage with 0.5W/5W. Unfortunately I discovered only tonight that the Wouxun has no ability to monitor VHF. The less powerful Btech GMRS-V1 can monitor VHF.

When I think about the requirements of a fixed or mobile neighborhood incident command post, it seems there is no one GMRS radio to rule them all. As far as I can tell it seems to require a minimum of 2 different radios to have ability to use >10W (conducted) on main channels + 5W on the 462 MHz interstitials + also politely use FRS 8-14 (0.5 W maximum/467 MHz interstitials). I guess a the best idea for a compliant base station that I can think of so far is a Kenwood TK-880 (no H assuming H's low power is 10W) plus a better FRS radio (On net, Jay mentioned Radioddity FS-T1has a lithium battery and a higher output power than the bubble-pack FRS radios, esp. the ones that use alkaline or NiMh batteries).

Wild speculation: Maybe there is a way to attenuate the power of a legacy Part 90 UHF transmitter by modifying the automatic level control (ALC). I have an idea some fanatic amateurs do that with HF radios, the ones with the hobby called QRP. Again I want to emphasize the FCC's "not our intent" to prohibit GMRS licensees from using surplus Part 90 equipment. Some earlier threads in this forum don't seem to acknowledge that. I don't say the intent was to violate today's GMRS power limits. But I see no rule against a GMRS licensee using (or modifying) legacy Part 90 gear if the use complies Part 95 requirements.

[Doug Mosher]

Great information, thanks all! Always learning...

Agree, there's no "perfect" GMRS HT yet. We (GENOAK - https://www.genoak.org/radios/) recommend the Wouxun KG-805G 1st, the BTECH V1 2nd. Both are fine and capable radios.

The feature to monitor VHF, including NOAA weather, as the V1 has, is definitely useful and I wish the Wouxun had included that receive-only capability. Note that the Wouxun does receive-only UHF frequencies 400-470 MHz, so can be programmed for example to listen to ORCA's WB6NDJ 440 repeater frequency, giving the ability to hear (some) Ham radio communications in an emergency.

Since the Wouxun doesn't use the ubiquitous AT1846S single-chip transceiver as does the BaoFengs and V1 (and many others), incorporating VHF monitoring is not a simple matter. I asked the president of buytwowayradios.com (co-creator of the KG-805G) if a future version could include VHF monitoring, and he said "not likely" (but didn't say no). That wasn't in its design specs.

In terms of features and cost, the V1 gets the nod. But there's more to our recommendation than missing features or some difference in output power (5W on the Wouxun (claimed--I see about 3.5W on my SWR meter) vs. 2W on the V1 is, practically speaking, not going to make a huge difference, as evidenced by our testing. Antenna and location play a larger role.) There's also ease of radio use and how well the radio will hold up to consider.

The Wouxun, without the front keypad and with the dial for channel selection, is IMO a much easier radio for an "average" person or neighborhood group to use. And the dual-transmit PPT and split screen on the V1 is nice for some folks, confusing for others. A confusing device isn't desired in an emergency. We by default CHIRP the V1 for GENOAK to disable the double PPT and sync the screen to display channel+name. Less confusing (and yep, less functional). Simplicity gives the definite nod to the Wouxun.

In terms of quality, the Wouxun seems (and is claimed) to be a more rugged design. I haven't and won't try purposely drop testing either. The Wouxun feels more like a Yaesu VX-6R (without the overloaded buttons) and the V1 more like the BaoFengs (from which it came). I've not had any BaoFeng (have one+ of each model) or the V1 fall apart, and doubt they will with normal use. The Wouxun is also IP55 water resistant, I can't find any rating for the V1 (or BaoFengs) and assume if it were rated, they would tout it. In terms of handling abuse, we give a slight nod to the Wouxun.

Another option we considered is careful programming of the BaoFeng BF-F8HP. Its 1W low power is still above the FCC FRS allowance though, so can't recommend. It appears a bit more rugged than the UV-5R line, but that could just be marketing hype. The problem we have (aside from FCC cert) is giving folks who aren't Ham-licensed an easy way to transmit on Ham frequencies. Too bad there's no way to program it to "receive only" on non-GMRS frequencies (maybe there is and I'm missing it?). Another aspect of the BF line is that they can transmit on the NOAA frequencies (162.400 - 162.550) and others that are frowned upon. So when programming the BFs I set those NOAA channels to be repeater channels with a +5MHz offset, figuring if I inadvertently press the PTT button while listening to NOAA, I'm not going to cause any slight interference.

-Doug

WQOY819 / KI6DOG

GENOAK - www.genoak.org

---------------------------------------------
 Doug Mosher
 OCP&R Program Manager
 Oakland Firesafe Council
 415.297.7457
 www.oaklandcpandr.org

[jayrfenton]

Hi Michael.  The baofeng uv-82 can be found on Amazon as a profung uv-82; profung is the  manufacturer of baofeng and many private labeled radios. The b-tech hts are relabeled baofengs while their line of mobile radios are from another source. 

This is a classic case of what I call "manufacturer denial syndrome" (mds). In this matter I will call it importer denial syndrome. In such matters I find it best to do my own fact finding. The v1 has been on the market since 2017 and the stated output has been 2/5 watts until recently. I just tested serial # ...7323 which was purchased about 3 months ago. The output was 2.0/5.1 watts and the manual showed the tx power @ 2/5 watts. I'm now seeking the serial numbers of other recent purchases. The fcc authorization appears to be valid with a high power result of 5.56 watts shown. 

You wanted the code for the diamond whip. I prefer the diamond srj77ca over the nagoya na-771 due lower swr readings such as 1.26 versus 2.4. 

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[Doug Mosher]

One other thing I forgot to note that is a potential issue with the BTECH GMRS-V1 is that the GMRS transmit capability is hard-wired to only channels 1 - 30 (repeater channels only 23 - 30). This means that if you want to add a couple repeater channels for the same frequency, for example for BeCERTAINN's regular and backup repeater modes (different PL tones), you have to sacrifice and overwrite another repeater channel. You can add the additional repeater channel as monitor-only above channel 30, but can't transmit on it.

This may not be a big deal unless a GMRS repeater is configured for several PL/DCS tones to allow different groups to utilize the repeater without hearing each other (could still interfere with each other) or if there are close proximity repeaters on the same channel. Then you're limited with the V1. The GENOAK GMRS repeater for example has several of these modes with different PL/DCS settings.

The Wouxun doesn't have this limitation as any of its 128 channels can be repeater configured.

[Brian Shiratsuki]

On Thu, Aug 27, 2020 at 1:01 AM Michael Gold <contac...@gmail.com> wrote:

> ...When I think about the requirements of a fixed or mobile neighborhood incident command post, it seems there is no one GMRS radio to rule them all. As far as I can tell it seems to require a minimum of 2 different radios to have ability to use >10W (conducted) on main channels + 5W on the 462 MHz interstitials + also politely use FRS 8-14 (0.5 W maximum/467 MHz interstitials). I guess a the best idea for a compliant base station that I can think of so far is a Kenwood TK-880 (no H assuming H's low power is 10W) plus a better FRS radio (On net, Jay mentioned Radioddity FS-T1has a lithium battery and a higher output power than the bubble-pack FRS radios, esp. the ones that use alkaline or NiMh batteries)...

that would be the fairest and most polite approach toward including
FRS. running 0.5 W into an actual half wave while contending
transmitters were running the same into typical permanently-attached
FRS antennas (as seen on the FS-T1) could yield a 10 dB advantage in
radiated power.

[Michael Gold]

Jay, and all, I discovered that yes, there was a design change to Btech GMRS-V1. For example when Miklor reviewed the product it tested out at 5W. The FCC database records a 2nd set of test reports ahead of the release of the 2W version. I'm surprised the FCC ID remained the same. And I'm surprised a GMRS-V1 purchased only months ago gives ~5W output.

As to the question of whether Pofung is basically the same organization as Baofeng, well Baofeng seems to deny it, yes, and Baofeng's warranty doesn't seem to cover Pofung UV-82. The two radios have different grantee codes (Btech/Baofeng is 2AGND and Pofung is 2AJGM). Different labs prepared different test reports. used different methods, and as far as I can see they came up with rather different power readings. I'm summarizing. The history of "the" UV-82 seems to be even more complicated than the history of the GMRS-V1. What a rabbit hole.

So as long as we are talking power levels of GMRS radios, the Baofeng GMRS-50X1 mobile unit has 3-level 5W/20W/50W output stages, with receive-only on VHF and FRS 8-14. It's ~$180.

[Don WQXJ891/NI6A]

Nice discussion. Maybe I can clear things up somewhat regarding the differences between BTECH (which is located at baofengtech.com) and Pofung etc. There is one state-owned radio company in China that mass produces Baofeng/Pofung radios. Anyone with good connections in China can bulk order radios to various specs from this factory if you order in bulk. They will not talk to you for small orders. BTECH has a special relationship with the factory for radios that meet BTECH's standards, hence BTECH will offer a 1 year warranty on their radios (few other companies do that).

 BECH radios spec out better than the common baofeng/pofung radios (uv5r, uv-82, uv82hp, BF-8HP, UV5X3, etc.) In short, if you buy your radio from BTECH you will get a warrantied radio to a hgher spec and not factory seconds or those made to very rock bottom cost-cutting specs.

Although the BTECH radios have a better quality build obviously commercial grade Motorola, type 90 Kenwoods and ICOM radios spec out better, but for 4 times the cost or more. I won't comment on the Wousan radios because O have not used them. Thanks for the reports.

To clear up previous posts, all the BTECH radios mentioned above can be kneecapped so as to not transmit on the ham bands via chirp. Simply uncheck VHF enabled and adjust the UHF frequency range to 462.000 to 468.000. Voila a knee-capped uv5r, uv-82, uv82hp, BF-8HP . Then do not program any of the FRS 8-14.channels. Now you have a radio that operates according to specs. But is it FCC listed for GMRS? No, not technically. But it will perform well and safely without any harm created to the amateur spectrum or any other agency.

Yes, the GMRS-V1 is a firmware knee capped version of the UV-82HP limited to 5 watts output (as tested). It uses all the same accessories as the UV-82HP and looks exactly like one.. Although very versatile,, they are not FCC approved or listed for GMRS operation. Regardless of what the manual may say, I suggest testing the GMRS-V1 for output power if that is your question.  You can't argue with a Bird Wattmeter or any other that is decently calibrated in scale.  use that as your determination. All the GMRS V1 radios that I have tested are approximately 5 watts output. Has anyone tested a newer model and only found 2 watts max output? Notice that it defaults to low power position upon boot-up.

Again thanks for all the good information.

73,

Don, WQXJ891, NI6A

[Mel McMurrin WREK301-KK6TMN]

Hi Doug and the group,

I've discovered a work-around for BTech GMRS V-1 to store 2 PL tones temporarily on the same channel using the upper and lower displays. Still a huge deficiency of this radio but this helps a lot with our 2-tone repeater checkins.
Very didactic tutorial here:
https://www.youtube.com/watch?v=OOx3-d6E5c4 

Cheers from Lake county,

Mel

[Brian Shiratsuki]

On Fri, Aug 28, 2020 at 1:55 AM Don WQXJ891/NI6A <saha...@gmail.com> wrote:

> ...To clear up previous posts, all the BTECH radios mentioned above can be kneecapped so as to not transmit on the ham bands via chirp. Simply uncheck VHF enabled and adjust the UHF frequency range to 462.000 to 468.000. Voila a knee-capped uv5r, uv-82, uv82hp, BF-8HP . Then do not program any of the FRS 8-14.channels. Now you have a radio that operates according to specs...

at least one sample of the uv82hp measured out of spec at high power
UHF (2nd harmonic at only -12 dBm when the spec is -16), but in spec
at the two lower settings:

<https://imgur.com/a/up2ne>

VHF was out at all power levels; so yes, unchecking that is a good idea.

brian

[Don WQXJ891/NI6A]

Brian, the link that you provided pertains to the uv-5ra not the uv-82hp or the gmrs-vi. Please send the correct URL. A $19 uv-5ra for that price is most likely the factory rejects/seconds. I don't think it is fair to compare that radio with the BTECH radios or the GMRS-V1. Have you done your own testing?

73,

Don, ni6a/wqxj891

[Michael Gold]

Don wrote

> All the GMRS V1 radios that I have tested are approximately 5 watts output. Has anyone tested a newer model and only found 2 watts max output?

Yes, see p9 of https://fccid.io/2AGND-GMRS-V1/Test-Report/Test-Report-3136322

1.89W at 462.625 MHz and 1.97W at 467.625 MHz

Considering the possibility that a 5W version of the GMRS-V1 was available as recently as a few months ago (per Jay), I am now somewhat disappointed at having just yesterday received a Wouxun unit that can't monitor VHF. The only reason I chose the Wouxun was the power rating being nominally higher than the Btech.

Doug M wrote

> 5W on the Wouxun (claimed--I see about 3.5W on my SWR meter) vs. 2W on the V1 is, practically speaking, not going to make a huge difference, as evidenced by our testing. Antenna and location play a larger role

The Wouxun test report to the FCC shows 5W, at least at 462.625 MHz.

https://fccid.io/WVTWOUXUN16/Test-Report/Test-Report-4695711

If a delivered unit did not measure up that would be another disappointment and maybe cause me to want to return the product to the vendor. See p9 of

If a unit did measure up, I personally consider 2W v 5W to be quite significant, that's 4 dB. Similar to difference between omni antenna and antenna with gain. Also enough to (at least partially) overcome cable losses in case I were to sometimes connect a rooftop antenna to an HT.

[Brian Shiratsuki]

On Fri, Aug 28, 2020 at 11:42 AM Don WQXJ891/NI6A <saha...@gmail.com> wrote:
> Brian, the link that you provided pertains to the uv-5ra not the uv-82hp or the gmrs-vi. Please send the correct URL.

sorry, there's a lot to scroll through on that page. the uv-82hp
material starts around the middle of the page, with the relevant plots
about 80% down the page. search doesn't seem to work.

> A $19 uv-5ra for that price is most likely the factory rejects/seconds. I don't think it is fair to compare that radio with the BTECH radios or the GMRS-V1. Have you done your own testing?

no; it sure would be nice to have access to a bench with such gear on
it. also, -16 dBm is a part 97 standard. part 95 may be more or less
stringent. the uv-82hp seems to be compliant with part 97 at medium
(4.6W) and low power. if the GMRS-V1 is a derivative design, it might
be fine at a nominal 5 or 2W.

brian

[Brian Shiratsuki]

the fcc.io page michael gold references implies that the part 95
standard is -13 dBm, and reports the worst figure for the 2W gmrs-v1
as -22.9, a wide margin pass. the page i referenced reports -12.63 dBm
for the uv-82hp at high power, so passing part 95 depends on the
rounding policy.

[Don WQXJ891/NI6A]

Brian, I stand corrected. Yes, the UV-82HP is tested as evidenced down the page. Thanks. Unfortunately, there was no picture of the UV-82HP and no indication if it was a factory second/reject or from BTECH. It did test compliant for VHF, but yes, we are addressing UHF which it was slightly not compliant. 

I am in total agreement that it would be excellent for the local radio clubs to pitch in for such bench equipment and then we can offer that service for all our members. I only have a nanovna (vector network analyzer) and a couple SWR/Power meters.

Thanks for the data.

73,

Don, wqxj891