Wouxun KG-UV8D for SO-50? Sure, but not full-duplex by itself...

Discussion in 'Satellite and Space Communications' started by WD9EWK, May 27, 2014.

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  1. K6LCS

    K6LCS Premium Subscriber QRZ Page

    This has become a pathetic "anti-Clint" tirade ... Sorry to bore most of you. Yes, Powerwerx will
    be feeding HRO these radios - that is common knowledge. And if Patrick truly wanted to determine
    the facts for himself, Powerwerx is open 40+ hours a week for inquiries.

    I make calls and write emails and get the answers to the inquiries I submit, and report what I learn.
    That is basic research methodology. NOTHING proprietary ... nothing "secretive." If anyone else
    wanted to fact-check me, they could make the calls themselves. Instead, this has become a
    "Clint said it - it must be un-true" thread.

    >> ... There has been no FCC press release indicating they are modifying or revoking the
    certification for the KG-UV8D.

    This statement tells me you have no clue as to how the FCC operates.
     
  2. WD9EWK

    WD9EWK Ham Member QRZ Page

    Does it? I think I have a pretty good handle on it, even though I'm not in the ham radio (or commercial two-way radio) industry, and not a lawyer fluent in telecommunications law. I read the Part 90 and 97 rules, something you didn't seem to have a handle on.

    Equipment certified for use in most radio services in the US appears in the Equipment Authorization Database. Many ham transceivers are listed with certification under Part 15 for their receivers covering outside the ham bands, but not certified for Part 97 or any other part of the FCC rules for their transmitters since that is not required under any part of the FCC rules when the transmitters operate in the ham bands. Only external power amplifiers operating under 144 MHz are required to have certification by the FCC under Part 97 before they are sold in the US. The last document added to the record for FCC ID WVTWOUXUN07 is in 2012. Nothing in 2014. No new radio has been listed for grantee code WVT (Wouxun) in that FCC database in 2014. FCC did not reject Wouxun's explanation that multiple model numbers would carry the same FCC ID number two years ago. These radios are still being sold in the US. FCC puts this information in the public domain, so there is no "he said, he said" disputes on what is - or isn't - legal for sale and use in the United States. Call it a "fact-check", Clint.

    Just like with the SO-50 thread I cited earlier, you can end the discussion by posting the information you claim to have from the FCC. Even with that, the Equipment Authorization Database still shows the UV8D as certified for use under Part 90. And, as we established very early in this thread, even before the reports in Clint's private Yahoo! group confirmed, this radio is legal for use in the ham bands. None of this would stop the FCC from making a change to the status of the FCC ID number in question, or for this radio, in the future. Just like in court cases, it is what you can prove - and I'm able to prove everything I've said using FCC rules and the FCC database related to this radio.

    Even with your misinformation and misdirection in some of your posts, Clint, I'll thank you for your contributions to this thread. I've become more familiar with the nuts and bolts of FCC Parts 90 and 97, the FCC Equipment Authorization Database, and my radios and what I can do with them since I started this thread in late May. I won't profess to have the knowledge of a lawyer that deals with the FCC, but I have enough to speak intelligently on what I've reviewed. I've made citations to what I'm relying on, if it isn't something I've done with my radios or photos I could just upload to this thread.
     
  3. K0RGR

    K0RGR Premium Subscriber QRZ Page

    The third harmonic of 145.85 is 437.55. That's 750 kHz away from the SO50 downlink frequency, and if there is any significant harmonic content being generated, I'd expect it to desense any nearby receiver, let alone one in the same radio. I'm even more amazed that the Baofeng didn't bother it when using an external diplexer. It could mean that the Baofeng transmitter is cleaner than the Wouxun - hard to say without a good analyzer. Yes, the other arrangement - UHF up, VHF down, should work much better with any radio.
     
  4. WD9EWK

    WD9EWK Ham Member QRZ Page

    Hi!

    What I see in the UV8D is similar to other radios that claim to be capable of full-duplex operation, like the old IC-W32A (newer versions of this radio would not work for full-duplex on SO-50, AO-27, or AO-51 - older versions were really good). When trying to receive on 70cm while transmitting on 2m with that HT, there is desense. No desense when using a separate radio for the transmitter. It's probably related to filtering and/or shielding inside the radio itself.

    I'm hopeful that radios like this UV8D or the old IC-W32A would work with the frequencies reversed (70cm uplink with 2m downlink). I know my W32A did fine with the ISS cross-band repeater in years past, even though it was no good for SO-50 or the other FM satellites we had at that time (AO-27, AO-51). It may be a year before we can find out with Fox-1, but there are other satellites with FM repeaters that may be available to us before Fox-1 is launched. If the UV8D won't work full-duplex with an FM satellite like Fox-1, a $30 Baofeng UV-5R can work as a transmitter, using the better receiver in a UV8D to hear the satellite.

    73!
     
  5. N8HM

    N8HM Premium Subscriber QRZ Page

    Here's the math for two separate radios with a single antenna and a diplexer:

    A decent transmitter should have the third harmonic about 60 dB down from the 2m signal, the diplexer adds another 60 dB of attenuation to that third harmonic. At 5 watts (37 dBm), that means that the third harmonic that enters the receiver is about -83 dBm. If a received signal of -83 dBm 750 kHz away desenses the receiver, it's a terrible receiver. Remember that an S9 signal is 10 dB stronger than that (-73 dBm or 50 uV in a 50 ohm system).
     
  6. W5PFG

    W5PFG Premium Subscriber QRZ Page

    Apology accepted.
     
  7. WD9EWK

    WD9EWK Ham Member QRZ Page

    I forgot to post a follow-up to my comment about using my UV8D on the LO-78 (LituanicaSAT-1) satellite Sunday afternoon...

    I used my UV8D as my receiver to work LO-78, transmitting with a Baofeng UV-82 like in a photo early in this thread - both radios connected to a Comet diplexer, then the diplexer is connected to my Elk log periodic. I set the UV-82 to transmit in narrow FM on 145.950 MHz with a 67.0 Hz PL tone, receiving around 435.175 MHz +/- with the UV8D, and the UV8D was tuning in 2.5 kHz steps. Performance was similar to what I saw when working SO-50. I didn't hear the satellite at low elevations (below 15-20 degrees), and had to tune quickly with those smaller steps, since LO-78 is in a lower orbit (around 300km) compared to SO-50 (around 700km). I made one contact, with K8YSE/7 here in Arizona (not too far southeast of my QTH), and heard another station that K8YSE/7 worked. The bigger issue was with my transmit power. I was not getting through the satellite clearly until it was up about 30 degrees or so from the horizon at 5 watts. I had an easier time when using my IC-2820H to work this satellite, and using slightly more power (15W). As the satellite descended to lower elevations before LOS, I was back to having difficulties getting through at 5W. I have seen others comment about some difficulties getting through this satellite with lower transmit power levels, so this is not a surprise.

    I don't plan on repeating this test, but using my IC-2820H as the transmitter with the UV8D as receiver. I'm confident I would see what I have seen previously, an easier time getting through the satellite at lower elevations with a little more power. This was a one-off test, and satisfied my curiosity about using the UV8D (at least as a receiver) to work LO-78.

    Since LO-78 was launched from the ISS, and its orbit is now down to 300km, we don't have a lot of time left with this satellite before its reentry. While it lasts, it is nice to have a second option for working FM via satellite. :)

    73!
     
  8. WD9EWK

    WD9EWK Ham Member QRZ Page

    Hi!

    Looks like Wouxun has gone through and secured a new FCC ID number for the KG-UV8D. In the FCC Equipment Authorization Database, there is now a new WVTWOUXUN10 ID number (grantee code WVT, product code WOUXUN10). This certification was issued today (16 July). The certification is Part 15 certification, only for the receiver in the 144-148 and 420-450 MHz amateur bands. This would mean the new version of this radio should not have any coverage outside the two ham bands.

    Ham Radio Outlet's web site has the KG-UV8D on it again, but claiming it is "version 3". MTC had taken it off their web site, but now it is back, claiming it has transmit ranges of 144-148 and 430-450 MHz, with receive ranges of 136-174 and 400-480 MHz. HRO and Powerwerx are claiming these radios are Part 97 approved, and showing the same ranges as on the MTC site except that the 70cm transmit range is 420-450 MHz. This is, again, not correct - since FCC does not certify equipment under Part 97, except for external power amplifiers operating under 144 MHz. If these radios will carry the new WVTWOUXUN FCC ID number, they are certified under Part 15 for the receiver, but the transmitter is not certified since that is not necessary under Part 97.

    It will be interesting to see this version of the KG-UV8D in the stores. It probably won't do full-duplex for SO-50 and other V/U FM satellites, but it would be an interesting change if these radios only cover the ranges in the FCC certification grant (no non-ham coverage on either band).

    73!
     
  9. ND5Y

    ND5Y Ham Member QRZ Page

    Interesting. The new FCC ID also apparently covers models KG‐UV7D, KG-UV9D, KG‐UV83, KG‐UV86, KG-UV66, KG- UV899, KG-UV8A, KG-UV8E, KG-UV8F, KG-UV8G, KGUV8H, and KG-UV8K.
     
  10. WD9EWK

    WD9EWK Ham Member QRZ Page

    Yup, Wouxun did the same thing with this FCC ID number as was done with the WVTWOUXUN07 FCC ID number. It is interesting that neither Wouxun nor FCC has made any changes to the previous WVTWOUXUN07 FCC ID number or the grant for that number.

    73!
     
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