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M-104C to M-106C

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freecell said:
it's not that good, the use of the term "skip zone" in the context presented is incorrect.
Touche freecell, but my post was so good that everyone understood what I was saying and you only succeeded to make yourself look like an ass. I'm OK with that. ;)
 
that's why you're using your unfamiliarity with the terms you throw around in some pseudo-authoritative manner as an occasion to resort to name calling. don't blame me for your inability to do your homework before you open your mouth. your spiel about the gamma match was equally ridiculous.

".......gamma was designed to operate at higher power levels and will not be as efficient at lower power levels." bullshit. the gamma match does one thing and one thing only. it provides a match between feedpoint impedances that are less than 50 ohms to 50 ohm feedline. if it's rated to handle 2kw of power it does its job just as well at 2kw as it does at 2w. as long as impedance equals voltage divided by current the gamma match performs its primary function up to the limit imposed by the materials from which it is constructed, period. the ratio between voltage and current that establishes the match transformation values don't change just because the power applied is varied.

replace "skip zone" with "skywave coverage area" and then that part of your post might make some sense. there are no communications taking place with any stations located in the "skip zone".
 
Now now freecell, relax. You know and I know what I'm talking about and I didn't call you an ass, I said you make yourself look like one. There is a difference.....if you want to argue semantics.

freecell said:
the gamma match does one thing and one thing only. it provides a match between feedpoint impedances that are less than 50 ohms to 50 ohm feedline. if it's rated to handle 2kw of power it does its job just as well at 2kw as it does at 2w. as long as impedance equals voltage divided by current the gamma match performs its primary function up to the limit imposed by the materials from which it is constructed, period. the ratio between voltage and current that establishes the match transformation doesn't change just because the power applied is varied.
Nice try, but you didn't address my statement. You unsuccessfully tried to steer the conversation in the direction YOU want to go. Take a 2KW gamma and a 5KW gamma and test them. When done, come back here and let us know what you learned. Better yet, test the 2KW against the 30KW gamma to clearly see what I'm talking about. Just in case you missed it, I'm talking "EFFICIENCY". We'll be patiently awaiting your results. Please be sure to describe your testing proceedures.
 
the word is semantics. you don't know how to spell it let alone debate it.

when you can tell me what a gamma match doesn't do "efficiently" then i'll know what to look for. i've already addressed it.

until you've pointed out what quality or property your use of the term efficiency deals with or to what degree this quality is exercised or quantified i have no idea what you're talking about and neither does anyone else.
 
Done already? Where are your results? Where are your testing parameters?

Thanks for the heads up on my improper spelling. I fixed that.

My post is clear. I am addressing the EFFICIENCY of a larger gamma used in a lower power application. What do YOU think that could mean? I know you can figure it out.....I have faith in you!

freecell said:
when you can tell me what a gamma match doesn't do "efficiently" then i'll know what to look for. i've already addressed it.
Transfer energy, duh! But the statement above confuses me, how can you have "already addressed it" if you don't even "know what to look for"?

freecell said:
until you've pointed out what quality or property your use of the term efficiency deals with or to what degree this quality is exercised or quantified i have no idea what you're talking about and neither does anyone else.
Please spare me your omnipotent opinion that you even have a clue what other people understand. Speak for yourself oh wise one.

Now that I've clued you in, please set forth and test and let us know what you learned.

I'll help you out! Make a single driven element and feed it with a 2KW gamma at 100 watts. Take a field strength reading. Then take a 30KW gamma and repeat. You may make any adjustments you want to the element and gamma for both tests. Let us know your findings!
 
You guys crack me up....arrows going one way, then back the other.
laughingsmiley014cm9.gif
laughingsmiley014cm9.gif


What I have read in some antenna books have been; lower to ground (yagi-horizontal) the best for short "dx". The higher you go the better it is for the longer "dx".
But going to high may not be a good thing either. Like MC was saying, using the crank up tower can be the best way of finding the right height.


I am right at 36' with my beam, it works just fine at that height. But my location makes it that way, I have nothing around me to block the signal and I am only 30' above sea level.

Location, location, location!
 
freecell said:
why is the larger gamma not as efficient at the lower power levels?
I don't know. I hope you can shed some light on it!

A local here has a M-106C. He also has a bowl box (that's not a good thing) running 6 3-500s (shoot me now!). He smoked his first gamma and got a replacement. We did a few minor upgrades to the 106 and installed the replacement stock (2KW) gamma.

The antenna tested fine and he ran that with just the driver for a while. The urge to flip the big switch was just too much but he knew he had to have a larger gamma or he would arc it also.

He went out and bought the 10KW gamma. We were surprised that there was a drop in signal on the receive. We tested the antenna and all was good.

Over a bit of time he was still unhappy with the performance of the antenna so we took some time one weekend to do some tests.

We swapped out the gamma for the 2KW version and bang, his receive was back on track. I have a Bird 4030 field strength meter so we took a couple of field strength readings; up close, approximate 1 wave length away, and a couple of miles away. Nothing scientific, but very repeatable. Then we installed the 10KW gamma and did it again.

With all other parameters being the same and using approximate 100 watts, we were surprised that there were consistently better field strength numbers using the 2KW gamma.

Obviously the 2KW gamma would not survive the big amp. The (for lack of a better term at this point) plates of the gamma were too close on the 2KW and would arc. The 10KW has more spacing. In order to compensate for the larger spacing, the 10KW gamma uses larger tubes.

It is my OPINION, that the increased spacing lowers the effciency of the feedpoint matching network. In other words, a lower amount of signal is making it to/from the driven element.

The fact is, something IS lowering the efficiency of the feedpoint matchin network as proven by the field strength readings. Remember, the ONLY change was the gamma.

I've talked to other people who have seen the same thing when going to bigger gammas. They however did not take any test measurements.

So now its your turn! You are a respected man on this forum (although your people skills suck at times) and your opinion and teachings carry some weight! So test away and prove me wrong. Don't use your books and keyboard however, do a real world test and let us know what you've learned!

Antenna THEORY amazes me and I learn more and more every day! Even the great ones out there say its a best guess when it comes to antennas and like me, they too learn more every day!

Screamn' whitewall tires and a guitar by his side
Billy's got the fever as he rolls on thru the night
Some were born to listen, some were born to play
He was lightning on the highstrings and thunder on the bass

He could play it high, he could play it low
He could make it cry, he could make it moan
He knows when push comes to shove
The proof's in the pickin'

The PROOF's in the pickin' !
 
Master Chief said:
He could play it high, he could play it low
He could make it cry, he could make it moan
He knows when push comes to shove
The proof's in the pickin'

The PROOF's in the pickin' !

AMEN TO THAT :!: :!:
 
Master Chief,
Yeah, and Rich Measures was/is not well liked by several name brand manufacturers! :)
Does some nice mods though.
- 'Doc
 
This may be true, but it doesn't mean he's wrong!

This thread is has drifted considerably. If we are done with the original questions, I'll lock it down.
 
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