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I read you five

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  • I read you five

    It gets a little irritating when you hear this more times than not. I am mindful of kicking the tail around towards the transmit target because they can't hear you especially worse from the ground.. Ok one problem was wind sock and replaced it but that just caused distortion on Tx audio. The real problem i'm thinking is VSWR. I'm guessing these radios are being fitted in the MTO's without a VSWR test. Just having a standard antenna fitted. I used to repair emergency service radios and other transmitters and they were generally way out of tune in the final output stage. Civilian radios were set out of tune to reduce the out put to about 5W to 10W. this is because of the ACMA regs. The only way to really know how your radio is performing other than "I READ YOU FIVE" is to bench test with a Marconi bench lab and a registered test license. and i don't have a spare $50 K for this equipment. Secondly if you had a simple VSWR meter you could see how well your antenna is performing as they could be way out of resonant frequency bandwidth or impedance value out of spec and causing big return loss. I guess using 123.4 chit chat channel will give you an idea of how crap your radio is but until you bench tested it you aint gunna be able to do much about it. Our antennas are mounted inside the tail too. Yeah feel the pain. I'm also guessing the antenna connections could be crap and nothing like ingress of moisture ad coax cable loves it just soaks it up like a wick. Some rubber amalgam tape can keep the moisture out of connectors or some large heat shrink not as good but better than nothing. AHHH wish i was back on the bench i could crank hell outa my radio could talk to the aliens. And how many other radios out there sound like CRAP Hmm might have a niche market here i can see ye's lining up for a tweak. Seriously there seems to be a lot of sick radios out there Squealing like hell and not hetrodine x talk usually induced electrical noise and yeah i had an easy fix for that too or the IF VCO'S stage way outa spec. Anyway there's my radio ***** for the day... feel so much better now.

  • #2
    Radios can be a source of great frustration. My experience is with UHF and at times you can talk to ground crew & they are hearing you loud & CLEAR then next day you wonder if the day before you were dreaming as they are not hearing you well. The former owner of my gyro had his system working beautifully but his helmet protection was a cloth cap & I wanted to use my helmet so a bit of adaption & a lovely system went to muck real quick. I replaced everything with a you beaut system from PMD race radios & the uhf was unreadable & there was a constant electrical noise through my earmoulds without breaking the squelch & the noise got louder at cruise revs.
    I was about ready to set fire to the lot when I tried a separate battery, a win, electrical noise gone however still crap transmission being nearly unreadable. I enlisted the help of my mechanic mate & half a day later after moving everything all around the cab we eventually got it working okay.
    My old Rosco with the suby 2.2 was interesting as you could have the radio working just fine then with no warning something would happen that would make my transmission unreadable. The only remedy was to pull uhf out & put a brand new one in & it would work beautifully. I sent about 3 uhf s back to GME & nothing wrong with them but put back in the gyro, no worky !!


    • #3
      hello brian, I sent mine to chook in WA. he gets on here and could probably tell you everything properly but in a nut shell the engine sound gets into your head piece [ ear piece ] and travels down the mike boom . the part going to the mike piece at your mouth and then obviously gets into your send message. chook matches up a mike piece to suit your gyro , basically what side is the exhaust on compared to your mike piece. what engine . that sort of stuff.
      get good ear gel cups etc. etc.
      I was going to chuck in a rotax joke here but deleted it as I'm being serious as radios can be hair pulling stuff for sure.
      you mentioned that increasing speed to cruise can cause it . = more engine noise etc etc
      also for "no warning something can happen" ,= could be just turning your head and letting the engine and exhaust noise in into your ear head piece and travelling down the mike boom.
      a mate had a pitts and said he could only transmit if his head was turned I way so that was in a plane too.
      I'm not a guru on anything but that's close to solving or helping solve in a direction for you.
      hope your been good brian. long time no hear. ok even that wasn't a radio joke .


      • #4
        Yeah, thanks Tony, radios can be challenging but when they are good its a wonderful feeling. Reckon you are right on there re turning your head as when you are working there's a lot of head turning & sometimes guiding ground crew onto stock at same time so I will try that tomorrow. If I had the time I would take the gyro over to chook & let him loose on it cause at the moment I have a noise cancelling mike & boxes for this & that before it goes into the UHF so it probably needs all pulling out & starting from fresh & that electrical noise really should be fixed before anything else is started. All I did was to remove the lead coming out of the front of the GME 3200 for my push to talk & mike & plugged in my earmoulds into the rear speaker & it went from 5/ 5 to absolute garbage.
        Yep been good but looking forward to a sea change real shortly.