I wonder if the power supply interferes with the radio - maybe..!!!

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by ZL1VSF, May 15, 2015.

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  1. ZL1VSF

    ZL1VSF Ham Member QRZ Page

    In the past, I haven't had too many kind things to say about my Wouxun KG-UV950P quad band radio. It's true, mainly because (and I still say) it shows many signs of being a poorly designed radio, especially in the receive department. It could be that it just needs to evolve and in the future (if there is one for Wouxun in amateur radio), it's offspring might eventually become a much better radio - well, maybe...!!! I got a little tired of its bad habits a while ago and ended up buying a Yaesu FT-8800R as a replacement and this has proven to be a radio truly worth having. "Magnificent", is the only word I can find to describe it...

    I unplugged the KG-950P at the connector, leaving the power lead still plugged into the switch-mode PS, and sort of decommissioned the 950P on the spot in favour of the new FT-8800. I used its plug to fire up the FT-8800 and since it went perfectly from instant ONE, I left things as is. I also re-fired up an older Icom IC-207H dual band with single band display, which also seemed to beat the 950P hands down in performance, no matter which way you cared to compare them (except for the dual display on the 950P). The IC-207H was plugged into my old faithful 20amp linear PS,, had it for about 25 years now, never been turned off except for a few power cuts over the years..

    The 950P sat there over the past 3 months, then just 2 weeks ago I had to listen to two frequencies at the same time (apart from the FT-8800) for a particular event and unplugged the IC-207H power lead and re-plugged it into the 950P. Oh dear, I wasn't looking forward to using this radio again. Nightmares of bad things flooded back into Dodge and I knew it would probably be only a matter of time before the plug was once again pulled. Well, to my surprise I used the 950P all weekend, both receive and transmit and it never missed a beat. I had it plugged into the linear PS in one end and a lesser gain antenna (Discone) in the other, and things could not have been better from this radio... It struck me just last night that I haven't actually noticed it there and that sort of says that's a good thing,, better than noticing it for all the wrong reasons. One major thing that has NOT shown up so far is overloading and lots of receive killing noise, both from a high gain antenna and also from a poorly made receiver section... Nor has the weird acting display which seemed to change volume levels (showing volume levels intermittently on the display) by itself. It used to also re-power itself back up when switched off, every now and then. It has done that just once, two nights back. I swear that it is a new radio (not in "age") now. It just isn't the same one I bought 6 or 8 months ago, still not perfect by any stretch of the imagination, but a darned sight better than before...

    Could it have been the switch mode PS all along that made it play up..??

    Yet the Yaesu FT-8800R, plugged into the switch mode PS, has no such issues.. Like I described it back up the page - it's magnificent...

    Al... (ZL1VSF)
  2. WA9WVX

    WA9WVX Ham Member QRZ Page

    Hello Al,

    I think the only way to consider your Switching Power Supply as a possible problem would be to have both transceiver's Schematic Diagrams opened up and comparing the +13.8 VDC Input circuitry. First problem would be getting the
    Wouxun KG-UV950P Schematic if they are even available to the Amateur Radio Community and then while comparing the circuitry, I'd be looking an internal L-C filter to smooth out / reduce any possible noise that might be on the Switching Power Supply DC Output.

    You've got remember that YAESU's engineering team has evolved through the years they have been in business and the Japanese are well known for their Quality Products. Whereas the Chinese Wouxum Products haven't been around that long, they're dirt cheap to purchase which in turn makes me wonder if they have the proper engineering staff, a Quality Control department looking for these exact failure problems or just manufacturing the products, doing a quick check on each radio for Tx & Rx and shipping them out the door. Once you see the Chinese really concentrate on Quality, expect their Products to increase in Price ... pretty much in line with YAESU, KENWOOD & ICOM.

  3. ZL1VSF

    ZL1VSF Ham Member QRZ Page

    Good reply Dan,,

    I'll see what I can dig up in the way of schematics for both radios and have a look-see... Generally, these power supplies seem to work ok on radio gear and are sold mainly here and Australia under two different names, but from what I know of them, they are a reasonably good PS,, made in China, true (what isn't nowadays) but good nevertheless.. Like you hinted on though, Wouxun gear, as I full know, is full of less than ideal quality that may show up in different areas but for once in its existence it's working for me rather than against me.. Actually, I could just leave things the way they are,, I mean it seems to be working well so why mess with it, right..!! A saying comes to mind - "If it aint broke, don't fix it".. Maybe those sorts of saying were invented for times like this - hahahaha...!!! Maybe I should just cross my fingers and hope it lasts as it is...

    Thanks for the input Dan... Cheers...

    Al... (ZL1VSF)
  4. ZL1VSF

    ZL1VSF Ham Member QRZ Page

    Just as a closing comment to this thread,, I have noticed that the UV-950P in fact is acting no different than its usual bothersome self. It has performed its usual "tricks" in flying colours, eg.. sometimes re-powering back up when turned off etc etc etc.. For a brief moment in time, I thought I was seeing the 950P as it was designed to do, not what it actually does, but I was wrong...

    I'm afraid it's the Leopard and its spots syndrome. Nothing has changed. I guess it is as I've always maintained, a potentially good radio spoiled by bad manners...

    THE END...!!!

    Al... (ZL1VSF)

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