Bob, what happened to your homebrew Gain Master project?

[Marconi]

Here is the post back in Feb, 2012.

me and a local decided to build a gainmaster from parts we have laying around the shack, if it works as intended we will build a higher power version.

 

[bob85]

one of them is at my ham buddy's waiting to be tested away from all his other antennas, vswr was up @2:1 mounted low without any adjustment,

when i test an antenna in my yard how i would normally use it and it loses out to my i-10k which in turn loses to the napco i lose interest.

 

[Marconi]

one of them is at my ham buddy's waiting to be tested away from all his other antennas, vswr was up @2:1 mounted low without any adjustment,

when i test an antenna in my yard how i would normally use it and it loses out to my i-10k which in turn loses to the napco i lose interest.

Did you check it to try and find out where it was resonant with the best SWR?

 

[Needle Bender]

I'm still wondering what is the impedance of the red coax used for the radiator & coil. If it's not 50Ω then...

Not to mention that even if the velocity factor of the coax casing used for the homemade isn't identical then the choke could allow the radiating lower half to be too long causing an unbalance possibly raising or lowering the TOA dramatically. It's an ingenious design but I'd presume a real biaatch to get right on the money without disassembling, and possibly destroying one from the factory to get exact values.

I plan to change out one piece at a time (for higher power handling RG-213) to get the correct measurements, though that choke coil will no doubt have me pulling my hair out!

 

[BOOTY MONSTER]

would be a whole lot easier to make a physically stronger vector 4000 , but cost a lot more unless you have the tubing already .

 

[Needle Bender]

would be a whole lot easier to make a physically stronger vector 4000 , but cost a lot more unless you have the tubing already .

I'd just use the whip from a Wilson5000 base load and a little solid stock for mounting it. That would allow you to shorten the tubing a good 5', relaxing the wind load a considerable amount. Plus I doubt you'd find the 5/16" diameter top in the neighbor's hedge like so many have in the past. {Cry_river}