I have tried many power mics and now I have given up after just purchasing a Silver Eagle for my 148GTL they all squeal. I can get them to work a little but when I run any watts it's no good and I almost have to just to make any contact up here in the mountains. I like loud audio and have to run a dynamic mic what kind if any non power mics offer more audio and preferably not a noise cancelling mic? Thanks
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Can't run a power mic!
- Thread starter hammer0630
- Start date
Have you tried any Turner mics... like the +2 or +3? I've not had good luck with Astatic power mics like the D104. They always want to squeal unless turned down real low, but I rarely can get a Turner mic to squeal regardless of the setting.
Also... does your radio have talkback? Power mics will sometimes squeal with talkback on.
Also... does your radio have talkback? Power mics will sometimes squeal with talkback on.
If you are getting a squealing problem ONLY when you turn on your linear amp; then it is RF feedback from the amp back into the radio. The problem is NOT the mic. You should have been able to figure that out already, because you have used many different mics and the same problem keeps on happening. Do you see that now?
It could be caused by a few things all related to your amp. For one, if you are using a LOT of watts with a big amp; that will throw a lot of RF into your radio room. But it can also happen with even a small amp. A large amp just makes all of the details done wrong just pop up into the open and so much more noticeable. Grounding the amp and the radio using braided grounding wire will help for a starter. Or possibly/probably 'common-mode current' coming from an antenna/coax setup done wrong. Other things too - and possibly compounded by many mistakes; but I will let others chime in an add if they want to. Need a LOT more details about your setup to begin with. Antenna model, antenna location/height, coax, grounding setup, etc.
It is one thing to have all of the neat radio gear, and quite another thing to make it all work in harmony . . .
It could be caused by a few things all related to your amp. For one, if you are using a LOT of watts with a big amp; that will throw a lot of RF into your radio room. But it can also happen with even a small amp. A large amp just makes all of the details done wrong just pop up into the open and so much more noticeable. Grounding the amp and the radio using braided grounding wire will help for a starter. Or possibly/probably 'common-mode current' coming from an antenna/coax setup done wrong. Other things too - and possibly compounded by many mistakes; but I will let others chime in an add if they want to. Need a LOT more details about your setup to begin with. Antenna model, antenna location/height, coax, grounding setup, etc.
It is one thing to have all of the neat radio gear, and quite another thing to make it all work in harmony . . .
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I am running ground wires from from nearly everything which does help but the only thing I can ground to is my house electrical ground. Now with or with out the extra grounding when I run power you can feel an electrical sting from any metal on the mic or the 148 even off the plastic knobs but not from the KL-500. I am using two power supplies for all my equipment is mobile. I am trying a mic called Superstar DM-5000 it has a jack on it made of metal which I am running a ground wire from it which will allow me to turn it up considerably but this does not work for my Silver Eagle?
this is rf coming back into the radio .you need to check your swr with the amp on and be sure its low enough .
you could try winding the coax into a choke right before the radio and see if that helps .
you could also try a snap on ferrite choke on the mic cord ,but that is just a band aid and wont cure the real problem you are having .
I don't see any mention of what you're using for an antenna. Whatever it is, I'd suggest a balun or at least a choke right at the feedpoint. And do you get the "zap" effect with all the mikes you've tried, or just some of them?
This is a classic case of RF floating around in the shack rather than being out at the antenna (what kind? how far from the shack? what kind of coax? how old?) - but I've seen - first-hand - that "zap" caused by a bad mike shield connection on one end or the other of the mike cable.
This is a classic case of RF floating around in the shack rather than being out at the antenna (what kind? how far from the shack? what kind of coax? how old?) - but I've seen - first-hand - that "zap" caused by a bad mike shield connection on one end or the other of the mike cable.
I am running 50' of the thick coax and it's only a couple of months old. I am using a Patriot 12 antenna and its 20' from the radio room and 25' up to the base of the antenna. I am running a Mega-Watt 36-40 amp supply which I have switched supplies and made no difference I have also used a different KL-503 and had same problem. All my jumpers are new with amphenol connectors. Incidentally when radio squeals and not turned up to much if you touch the 148 it will stop squealing also if it is turned up just before it squeals and the mic gets close to your mouth it squeals.
Hey hammer0630:
A month or so ago, you had a problem with your RM/Italy amp and it turned out to be the power supply. Now, you can't get the mic to work, even though you have used a bunch of them. Assuming that you got a better power supply and the amp problem is gone, you now have problems with RF in the shack.
Have I got that picture correct? Or should I dig up that post too? Seems to me, that your antenna/coax has always been a factor. So; what kind of antenna is it, how high is it up, how far away from the radio room is it, and what kind of coax are you using? Are you using braided grounding wire or just stranded wire? Same radio and amp too; or is the lineup different?
A month or so ago, you had a problem with your RM/Italy amp and it turned out to be the power supply. Now, you can't get the mic to work, even though you have used a bunch of them. Assuming that you got a better power supply and the amp problem is gone, you now have problems with RF in the shack.
Have I got that picture correct? Or should I dig up that post too? Seems to me, that your antenna/coax has always been a factor. So; what kind of antenna is it, how high is it up, how far away from the radio room is it, and what kind of coax are you using? Are you using braided grounding wire or just stranded wire? Same radio and amp too; or is the lineup different?
I believe we use to call it RG58-U coax it's not the mini commonly used in automobiles. I am using a Patriot-12..12' two piece fiberglass which I am seriously looking at the new Star Duster M 400. Coax is new, all jumpers new and factory made. Now possible cause maybe that the audio limiter is cut? I use to have a 148GTL with a Digi-Scan back in the 80's audio limiter removed,Silver Eagle a 5/8 ground plane and a moon raker 4 and a Maco 300 that set up had no audio problems. I am sure my problem is coming from using a mobile amp KL-503 but do not know the cure it seems to be with grounding any suggestions on getting a good ground in the house. Also my antenna is mounted to the eve's of my roof and the mast does not extend to the grouind below I have run a ground wire into the earth 7' just to see if it would help with clearing some static in my recieve....Jeff
Also wanted to add is I do have loud audio with the 148 stock mic and of course I can run it wide open and full wattage with no problem. The problem is the quality of the audio is not so great now that doesn't mean crappy but I like the sound of a Silver Eagle and the convienience of a desk mic. When using the D-104 I can open it a little and could live with that audio but when applying any wattage I can't open it at all and no ground wire or anything has helped with the D-104.
Thank You . . .
First of all, I have never owned the Patriot antenna. But from what I heard from many sources, it isn't a very quality built antenna at all. There have been many complaints from those who have bought/used it. Might want to Google it and not take my word for it. You could probably build your own dipole and it would probably work much better than your Patriot.
A ground plane antenna like a Maco V-58 is both a very popular and inexpensive antenna. The Patriot has no ground plane on it whatsoever. This is a problem. For that reason, it will use the coax as a ground plane/'counterpoise (Google 'counterpoise' and suddenly so much of what I am describing here will suddenly begin to make more sense). Which will lead that transmitted RF right back into the shack when using power and really mess with your radio and amp setup. I consider this a major problem from what you have told me here.
Part of the problem you are having has to do with the fact that your antenna is too close to your radio/amp. You don't want it right above you, and would be best if it was more than a few feet from the building. Get it as high as you can in the air - safely. Watch out for POWER WIRES/POLES! 36 ft high is ideal; but higher won't hurt either. Too low and you will just have the same problems regardless of what antenna you use - especially when using an amp.
Grounding the radio, power supply, and amp should be done by using 'braided grounding wire' - as opposed to using just normal stranded or solid wire. It will need to be connected to a ground rod. If you are close to the house ground rod, you can use that. If you are too far away; then you will need to put another ground rod in - as close to the shack as possible - and link the house ground rod to the new rod. Then attach them both using 10ga solid wire between those two points. Bury that wire between those two points; what you are trying to remove any possibility of a 'ground loop' - which is also important to do. That wire can be regular 10ga stranded wire if it is to be buried. In any event, that is what I can see and what I would do if I was going to run power as you do.
Use a choke coil beneath a ground plane antenna (5 winds of RG-58 coax on a coil form with a 4.25 inch diameter). Not much hope for your Patriot antenna though; even with this choke coil. Otherwise, just run the radio w/o the amp and you can keep using that Patriot. But I wouldn't; that is for sure. Your antenna, its location, and the lack of proper equipment and house grounding are major issues that you face - IMO . . .
First of all, I have never owned the Patriot antenna. But from what I heard from many sources, it isn't a very quality built antenna at all. There have been many complaints from those who have bought/used it. Might want to Google it and not take my word for it. You could probably build your own dipole and it would probably work much better than your Patriot.
A ground plane antenna like a Maco V-58 is both a very popular and inexpensive antenna. The Patriot has no ground plane on it whatsoever. This is a problem. For that reason, it will use the coax as a ground plane/'counterpoise (Google 'counterpoise' and suddenly so much of what I am describing here will suddenly begin to make more sense). Which will lead that transmitted RF right back into the shack when using power and really mess with your radio and amp setup. I consider this a major problem from what you have told me here.
Part of the problem you are having has to do with the fact that your antenna is too close to your radio/amp. You don't want it right above you, and would be best if it was more than a few feet from the building. Get it as high as you can in the air - safely. Watch out for POWER WIRES/POLES! 36 ft high is ideal; but higher won't hurt either. Too low and you will just have the same problems regardless of what antenna you use - especially when using an amp.
Grounding the radio, power supply, and amp should be done by using 'braided grounding wire' - as opposed to using just normal stranded or solid wire. It will need to be connected to a ground rod. If you are close to the house ground rod, you can use that. If you are too far away; then you will need to put another ground rod in - as close to the shack as possible - and link the house ground rod to the new rod. Then attach them both using 10ga solid wire between those two points. Bury that wire between those two points; what you are trying to remove any possibility of a 'ground loop' - which is also important to do. That wire can be regular 10ga stranded wire if it is to be buried. In any event, that is what I can see and what I would do if I was going to run power as you do.
Use a choke coil beneath a ground plane antenna (5 winds of RG-58 coax on a coil form with a 4.25 inch diameter). Not much hope for your Patriot antenna though; even with this choke coil. Otherwise, just run the radio w/o the amp and you can keep using that Patriot. But I wouldn't; that is for sure. Your antenna, its location, and the lack of proper equipment and house grounding are major issues that you face - IMO . . .
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