Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
Again, I just think it is wrong to tell someone the antenna won't work
with out a choke. Well, obviously I've never said that. But I have done many tests with 1/2 waves with and without decoupling sections. They were always improved with the extra section. I just mainly wanted to clarify that no matter how the antenna is fed, or no matter the SWR, which is totally irrelevant, you still have to contend with the spillover currents. The only cure for that is a decoupling section, choke, or whatever. As far as I know, the isopole was electrically the best dual 5/8 ever built as far as decoupling the line. I've never heard of any competing designs beating it. The ringo ranger II is slightly inferior. But the isopole is also pretty ugly...Looks like a missile... I'm not saying it doesn't work ok now. I'm sure it does. I'm just saying it would likely work a bit better with it, and be more stable as far as common mode currents per users at different sites. I agree. I don't think you should change it...There are other designs if you want higher performance..Anyone wanting to further decouple the line can add their own chokes, etc.. The ringo ranger II was cushcrafts answer to the isopole. Before that, they sold the ringo ranger. It was basically fed the same way as the J pole, except using the gamma loop. Like the version you use, the gamma loop ain't half bad at decoupling the line in itself. It was fairly usable as is, and many used it for a few years...Then the isopole came out, with basically the same dual 5/8 design, but with decoupling. It just tore the ringo ranger a new one... Smoked it....Cushcraft knew they had a major problem. So they designed a decoupling section to add below the regular ringo ranger. Made a *huge* difference in performance for most users. I know myself, I tested it with and without the decoupling section, just out of curiosity. On local repeaters, the average difference was 3-4 S units, using an icom 22u. And thats totally reciprical. On VHF/UHF, I've found that decoupling is generally more important to low angle gain, that any gains from element lengths, or collinears, etc... A well decoupled 1/4 wave ground plane can easily match or beat a poorly decoupled much taller ringo ranger with no section... Myself....I prefer a small yagi....:/ I have a three el for FM, vertical... Smokes any vertical....MK |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|