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New Gainmaster Power?

Mudfoot

Elmer
Jun 17, 2009
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Southeast Ohio
I have one of the first batch of these. Can't recall, but is 6-7 years old, or more.

Do the newer ones handle more juice. Seems I remember mine was <500 watts.

Anyone have a newer one, like year old?

What are you running, power wise?
 

The new ones have the same power rating. That being said, I do recall a thread from a while ago where Shockwave talked about a mod that could handle more power. It involved swapping out the coaxial capacitor with a different type of coax.

https://www.worldwidedx.com/threads...he-higher-wattage-version.100928/#post-350701

Skip down to post 16, on post 17 is a link to a thread that apparently no longer exists where it was originally posted...


The DB
 
Can't see the issue. Even going from 500W to 1kW is only half a S point/1 CB S point to the other end.
 
If they can't hear you with 500 they ain't gonna hear with a kw.
one of the reasons of not being able to make a contact is every one running an amp when
not needed..
Just think about what the guy on the receiving end must be hearing. How can he pick out a station to
answer when all he is getting is mass hetrodyne with many people calling running big amps.
Running high power is not always the best way to go.
if propagation is not good all the watts in the world are not going to make it happen.
Be patient, wait for a lull in the action & then try calling again.
 
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I remember that post. That's where I thought I read Sirio was gonna beef it up. I might do this mod when I take mine down. I've never ran anything more than around 300 watts.
 
I seem to remember hearing Sirio was going to do as HP model as well so I don't think you're remembering wrong, I just think it didn't happen.
 
The problem with the original and revised gainmaster power ratings is that sirio made them up,

some people get away with low duty cycle modes SSB/AM at 500w or more on a stock antenna,
but less than 300w of long winded fm will have your vswr rising often untill your amplifier leaks smoke,

Gainmasters handle about 200w continuous carrier without upsetting the vswr on long overs,
the issue is more than the capacitor not cut neatly or been too small,

Gainmasters use bieffe rg58 size foam dielectric coax,
http://www.bieffecavi.com/index.php?lingua=eng&pag=prodotti.php&categoria=coassiali50

ok for 300w continuous or providing vswr is very low 600w with the coax getting pretty warm,
the same power will cook rg58 size coax if vswr is very high

only the coax from the gainmasters so239 connector up to the matching stub has low vswr, the coax between the stub & feed point has high vswr & should be derated accordingly,
the stub also gets hot as hell with 300w fm.


simonthewizard did say something about a higher power version maybe in the pipeline.
 
Hello Bob.

I recall recently seeing an old schematic image I saved on my computer indicating the GM used RG 303 cable.

See attachment below. Here it shows where the destruction occurred.

I don't recall if I was able to see printing on my GM cable after lightening destroyed the antenna, but I will try and find it. In the last 3 years I've put a lot of my antenna stuff in storage, but I will try and find this old coax and report what I find in this regard.
 

Attachments

  • GainMaster struck by lightning #1.JPG
    GainMaster struck by lightning #1.JPG
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  • Gain Master struck by lightening.pdf
    173.1 KB · Views: 11
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