Bleed over for Solarcon (Antron) A-99

[W5LZ]

Those ferrite chokes should go as close to the antenna's feed point as is possible or practical. They slip over the coax and are 'stacked' (one usually does no goog). How many should you use? As many as you can. That gets sort of expensive, so a coaxial choke (coil of coax) is also usable. How many turns for that coil? Something like 4 - 6 ought'a do it. Something like 6 - 10 inches in diameter depending on the coax used. Just don't wind it too tight.
- 'Doc

 

[northern35s]

A ferrite choke is a piece of cake to make, however just checking the figures for a coax choke, if single band is all you need (I was thinking multiband) then 5T of RG58 or RG213 on a 4.25" air cored former will give a very respectable figure for 27MHz, any more turns than that and the high impedence point will lower in frequency, if you use a wider former the same will happen, and a narrower former wil move the high impedence point higher.

It's always good to check rather than shoot from the hip :blushing:

 

[ebayguy]

Those ferrite chokes should go as close to the antenna's feed point as is possible or practical. They slip over the coax and are 'stacked' (one usually does no goog). How many should you use? As many as you can. That gets sort of expensive, so a coaxial choke (coil of coax) is also usable. How many turns for that coil? Something like 4 - 6 ought'a do it. Something like 6 - 10 inches in diameter depending on the coax used. Just don't wind it too tight.
- 'Doc

That's what people were telling me to do with a 2 liter bottle, and one person suggested a 4" pvc pipe. I have gotten so many different things said, I am getting confused. Now, if I get some of those ferrite chokes, at the inner diameter for the LMR-400, the antenna feed is at the coax/antenna connection? Then take and do a coax choke below that? What diameter should LMR-400 be for maximum effect?

 

[ebayguy]

(I was thinking multiband) then 5T of RG58 or RG213 on a 4.25" air cored former.

Well, that would depend on what is considered multiband? I run a Dak IX, (sorry for the typos earlier ie IV), for a base 90% of the time, but I also have a power supply to run either my Galaxy 88, or my Connex 3300HP, and I want to get my Ameteur Radio license for atleast 10 meter. I usually don't talk on SSB, that's why I have the IX, and not the X. I might talk on SSB later, once I start making more contacts, but for the moment, just AM.

How many turns for the LMR-400?

 

[BOOTY MONSTER]

here's some info of making chokes .

http://www.worldwidedx.com/cb-antennas/62990-coax-choke-info.html

FWIU ...... using the 99/2000 type antennas with a choke at the feed-point , isolating the antenna from the mast and adding 1/4 wavelength ground elements to it has the best chance of eliminating CMC's . if the radio/amp is being over modulated or over driven , having a better antenna setup isn't gonna eliminate the problem .

 

[northern35s]

Steve Hunt's, G3TXQ, choke data is is a golden gift to anyone looking for free, easy to understand, information with regard to coax chokes, it's my one stop shop for data on the subject

 

[Mudfoot]

The whole purposes of the RF choke is to impede the flow of common mode current on the coax, an vertical antenna that doesn't have any radials / ground, requires the coax to form the other half of the antenna, this being the case then the coax choke will fail in it's purpose, it won't be able to impede the common mode current, the only time this does work is if the antenna is mounted on a metal pole, then the coax will choke, however the pole will then carry the common mode, this may cause excatly the same problem, you may be lucky and it doesn't.

If the A99 had a decent set of radials then a coax choke stands a much better chance of working, and if you really want to ensure the choke does it's job then you need to consider a torroidal ferrite cored choke

I know the purpose...

Just pointing out that it'll help more than it will hurt. Plus, all it costs is a few extra feet of coax wrapped around something free.