I have a cushcraft MA5VA which I bought second hand.
I find that I can only get close to 1.5 SWR on the 12 meter section of this antenna. All other sections show >25 SWR on my 259C.
When testing, I will set the 259C for the desired band and then try to get a SWR reading close to 1:1 in that band. I will then sweep up the bands and try to get the same results in all other bands on this antenna. I was told to touch the end elementof the band under test and see if it changes the results on the meter, and it will.
I am finding that when testing any of the other sections I can touch any element and it will affect any other section during testing, except for the 12 section of course.
Is there a step by step process that is spelled out somewhere that I can follow just to make sure I am doing this right? or does this sound like I have multiple coils that are damaged?
I have a cushcraft MA5VA which I bought second hand.
I find that I can only get close to 1.5 SWR on the 12 meter section of this antenna. All other sections show >25 SWR on my 259C.
When testing, I will set the 259C for the desired band and then try to get a SWR reading close to 1:1 in that band. I will then sweep up the bands and try to get the same results in all other bands on this antenna. I was told to touch the end elementof the band under test and see if it changes the results on the meter, and it will.
I am finding that when testing any of the other sections I can touch any element and it will affect any other section during testing, except for the 12 section of course.
Is there a step by step process that is spelled out somewhere that I can follow just to make sure I am doing this right? or does this sound like I have multiple coils that are damaged?
On Mon, 24 Jan 2022 07:13:23 -0800 (PST), Thee Middleone <theemi...@gmail.com> wrote:
I have a cushcraft MA5VA which I bought second hand.
I find that I can only get close to 1.5 SWR on the 12 meter section of this antenna. All other sections show >25 SWR on my 259C.
of the band under test and see if it changes the results on the meter, and it will.When testing, I will set the 259C for the desired band and then try to get a SWR reading close to 1:1 in that band. I will then sweep up the bands and try to get the same results in all other bands on this antenna. I was told to touch the end element
Jeff,I am finding that when testing any of the other sections I can touch any element and it will affect any other section during testing, except for the 12 section of course.
Is there a step by step process that is spelled out somewhere that I can follow just to make sure I am doing this right? or does this sound like I have multiple coils that are damaged?Manual:
<http://manuals.repeater-builder.com/Cushcraft/MA-5VA/MA-5VA.pdf>
I found this comment in a review at: <https://www.dxengineering.com/parts/csh-ma5va>
"Works well on all bands, requires careful tuning of the extendable
elements and the usable, low swr (1.2 -2.0) is narrow, about 100 khz."
I suggest you read the entire review as the owner also had a "won't
tune" problem.
Note that the extendable elements are part of the tuning.
Perhaps using a VNA will prove more accurate and allow you to see
narrow VSWR dips that are radically off frequency:
"How to use the NanoVNA to sweep / measure an antenna system's SWR and optimize its tuning"
<https://www.youtube.com/watch?v=xa6dqx9udcg> (6:06)
Also, testing a vertical antenna usually requires a counterpoise and grounding system. Testing such an vertical, laying on the ground
isn't going to work. Try assembling and installing the vertical in
something close to the typical operating configuration.
Good luck.
--
Jeff Liebermann je...@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
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