I followed Radio Works recommendations for RF feedback problems. Their line isolators and grounding ideas worked to cure a bad case here. _______________________________________________ Amps mailing
Seconding the message below I add my personal endorsement to Radio Works.com. When moving my shack from the 12 month "dxpedition" in Secaucus, New Jersey to my home in Kentucky, a severe case of RF f
Ditto for me downunder. The Radioworks line isolators do the trick nicely. You can make your own as they are just coax wound around a ferrite rod. You can also use the coil of coax like Rich suggests
The one I use has ferrite beads stacked on top of each other (about 50 of the little buggers!!) on about a 12 inch piece of teflon coax. Since it isn't a torroid, it can't be saturated. It's supposed
On Jul 31, 2004, at 10:21 AM, Joe Isabella wrote: The one I use has ferrite beads stacked on top of each other (about 50 of the little buggers!!) on about a 12 inch piece of teflon coax. Since it isn
Good point, Rich!! I guess I should say "DUUHHH!!!". I would imagine that the coax and/or PL-259 would be the weak link in this case though, wouldn't it?? Even say RG-400 or RG-303 would give up befo
Beware of the loss in the "beads" of the bead baluns. While they may not saturate, if there is substantial current on the outside of the coax you can see significant heating ... to the point of exce
On Aug 3, 2004, at 9:40 AM, Joe Isabella wrote: Good point, Rich!! I guess I should say "DUUHHH!!!". Rube Goldberg showed up that high-tech solutions are not always mo' bettah. I would imagine that t
Hello OT Use the black ties. They are special UV resistant . Used them on my early tower, they were still in good shape after eighteen years. Jos on4kj ( seventy years young black tied hi hi ) ______
You're right, Rich -- bad wording... My point was only that even at 1.5-2kW, the PL-259s or coax they're soldered to would be first to go. I'll stick with my bead balun -- it fixed all the RF problem
On Aug 5, 2004, at 3:04 PM, Joe Isabella wrote: You're right, Rich -- bad wording... My point was only that even at 1.5-2kW, the PL-259s or coax they're soldered to would be first to go. I'll stick w
R. Measures wrote: I'll stick with my bead balun -- it fixed all the RF problems I was having, so unless it bursts into flames, I'll keep it!! Joe -- the only problems that I have heard of is the fer
Following-up my previous message... Over its "wideband" region, a ferrite bead becomes increasingly resistive as well as inductive. The resistive losses in each bead will be I-squared*R and these wil
On Aug 7, 2004, at 1:18 AM, Ian White, G3SEK wrote: R. Measures wrote: I'll stick with my bead balun -- it fixed all the RF problems I was having, so unless it bursts into flames, I'll keep it!! Joe
R. Measures wrote: Joe -- the only problems that I have heard of is the ferrite beads getting so hot they cracked and dropped off. This is hardly surprising since the ferrite material that is typical
On Aug 8, 2004, at 3:37 AM, Ian White, G3SEK wrote: R. Measures wrote: Joe -- the only problems that I have heard of is the ferrite beads getting so hot they cracked and dropped off. This is hardly s
I found that the measured common mode impedance ona supposedly identical arrangement to the W2AU balun gave rather less common mode suppression. However, the losses about 5%, or about 0.22dB. That st
On Aug 10, 2004, at 12:23 AM, peter.chadwick@Zarlink.Com wrote: I found that the measured common mode impedance ona supposedly identical arrangement to the W2AU balun gave rather less common mode sup
Ferrites used in non-transmission line transformers can get quite hot at high power levels e.g.40kW. I've seen 50 - 600 ohm 40kW xfmrs: they used 2 legs, each with 24 rings stacked. Each ring was 6 i
Dear Peter, Some fourteen years ago, Rich Measures wrote an article that appeared in QST magazine called A BALANCED BALANCED ANTENNA TUNER. This design firstly moves the balun to the input of the imp