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   Home   Help Search  
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Author Topic: The Best Coax To Use  (Read 3135 times)
SV1IYF
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Posts: 112




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« Reply #45 on: October 30, 2017, 02:55:24 PM »

Obviously not retired yet..

As any sane wife knows that retirement brings males to the fold back state of their youth.
Consequently, the choice between stringing up wires around the house vs chasing the opposite sex (who read "she" knows where), is anything but a dilemma.
At least mine has this kind of common wisdom, even after approaching 50 years together.

73 Nikos
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KM6NFF
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Posts: 112




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« Reply #46 on: October 30, 2017, 04:24:31 PM »

Obviously not retired yet..

As any sane wife knows that retirement brings males to the fold back state of their youth.
Consequently, the choice between stringing up wires around the house vs chasing the opposite sex (who read "she" knows where), is anything but a dilemma.
At least mine has this kind of common wisdom, even after approaching 50 years together.

73 Nikos



Well put and good point.
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KM1H
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Posts: 2443




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« Reply #47 on: October 30, 2017, 06:12:48 PM »

Quote
A notable exception to this is a vertical dipole.

- Glenn W9IQ

As long as the bottom is at least 1/4 wave high and preferably 1/2 wave. Not easy to do for most HF bands. The snake oil brands are almost touching the ground and using the coaz as part of the radiator.

Carl
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W9IQ
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Posts: 1706




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« Reply #48 on: October 31, 2017, 06:23:34 AM »

Quote
A notable exception to this is a vertical dipole.

- Glenn W9IQ

As long as the bottom is at least 1/4 wave high and preferably 1/2 wave. Not easy to do for most HF bands. The snake oil brands are almost touching the ground and using the coaz as part of the radiator.

Carl

Carl,

This is a common misconception. As a simple example, take a 20 meter, center fed, 1/2 wavelength dipole and turn it vertically with the bottom end about 5 feet off of the ground. You will have an omnidirectional antenna with a little more than 1 dBi of gain at a 14 degree take off angle. And no ground radials needed.

To your point, if you can raise the antenna more off of the ground, the gain will improve but the maximum lobe will be at a much higher elevation angle and the gain will improve by a couple of dB. The 14 degree gain will drop by almost 2 dB.

To overcome common mode current difficulties, build the antenna from tubing and run the coax on the inside of the tubing, exiting at the bottom.

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
KM1H
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Posts: 2443




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« Reply #49 on: October 31, 2017, 09:41:24 AM »

Quote
This is a common misconception. As a simple example, take a 20 meter, center fed, 1/2 wavelength dipole and turn it vertically with the bottom end about 5 feet off of the ground. You will have an omnidirectional antenna with a little more than 1 dBi of gain at a 14 degree take off angle. And no ground radials needed.

No misconception at all and Im talking about real world performance and not dBi theory.
Been there, done that with low bottom end vertical dipoles on 40 and 20M over poor ground.

Another misconception is believing that low angle performance suffers. Various commercial band VHF and UHF verticals use stacks of folded dipoles that have fantastic coverage at 120' and 150' on 150 and 460 mHz with repeaters on one of my towers. When I tried an 8 tall stack at 120' for a 70 cm ham repeater I was getting complaints from other coordinated repeaters from up to 100 miles away. Im on a hilltop with a 3 degree negative horizon. After a couple of frequency changes with similar results the coordinators pretty much gave up and told the others to live with it. When used on FM simplex in contests the range was 150 miles+ most any day to others well equipped/located.
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W9IQ
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Posts: 1706




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« Reply #50 on: October 31, 2017, 10:23:04 AM »

Quote
No misconception at all and Im talking about real world performance and not dBi theory.

If you don't understand/appreciate the significance and applicability of an isotropic antenna to the field of antenna engineering and its related dBi metric, then I recommend you hit the books.

I could also say that the low verticle dipole I referenced has a 14 degree take of gain of -1 dBd if that helps.

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
KM1H
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Posts: 2443




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« Reply #51 on: October 31, 2017, 03:25:56 PM »

Quote
If you don't understand/appreciate the significance and applicability of an isotropic antenna to the field of antenna engineering and its related dBi metric, then I recommend you hit the books.

I could also say that the low verticle dipole I referenced has a 14 degree take of gain of -1 dBd if that helps.

- Glenn W9IQ

The usual put downs from you Glenn even when you couldnt stay on the subject Roll Eyes
I was studying antenna engineering and then practicing it at a real non ham job long before you were even in diapers. You might learn the practical real world applications before replying.


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W9IQ
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Posts: 1706




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« Reply #52 on: November 01, 2017, 03:25:38 AM »

Carl,

I didn't realize you are such a sensitive guy Smiley. I will be more gentle in the future. It wasn't intended as a put down - I did start the paragraph with "if"...

- Glenn W9IQ
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- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
KM1H
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Posts: 2443




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« Reply #53 on: November 01, 2017, 07:51:08 AM »

Quote
I didn't realize you are such a sensitive guy. I will be more gentle in the future. It wasn't intended as a put down - I did start the paragraph with "if"...

- Glenn W9IQ

It must be the inbred German arrogance that could use a bit of tempering.
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KM6NFF
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Posts: 112




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« Reply #54 on: November 09, 2017, 01:56:24 PM »

It looks like now I'm going from 50' to 100', so what is the best coax used for this length. I'm looking for the best performance possible. Thanks
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K6BRN
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Posts: 449




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« Reply #55 on: November 09, 2017, 04:41:07 PM »

Robert (KM6NEF):

Suggest you just go out and get 100 feet of connectorized Times Microwave LMR-400 Ultraflex or its equivalent for $130+tax and be done with it.

https://www.hamradio.com/detail.cfm?pid=H0-013170


Glenn (W9IQ), and Carl (KM1H):

You guys are too much fun to watch... the Man Who Knows Everything meets the Man Who Has Done Everything.  BOOM!

Glenn, meet Carl.  Carl really has done a lot in his life and has practical info on many topics.  It's worth listening to his advice, even if it's a bit gruff, then you can make your own decisions.  And, if you dis him, he'll hit you over the head with a verbal rolling pin, several times.  Think of him as a Gunny Sargent - rather than tell him he's wrong, ask "why" - he's got plenty of experience and opinions.  You might learn something, too.  But at least you'll have some input to consider.

Carl, meet Glenn.  Per his own admission, Glenn is the smartest person on the airwaves, never makes mistakes and is probably a registered member of MENSA, just like Spiro Agnew.  Not sure what THAT insecurity is all about, and I don't think he's an engineer - more like a computer science guy or IT professional.  But, all said, he probably has a pretty good brain, if he'd just stop stumbling over it.  In short, Glenn might be worthwhile to have a discussion with if it can be kept on a non-personal level and you guys might even have a pretty good debate - your interests overlap a lot.

Just Say'in, gentlemen.  You have more in common than not, so why not make it a positive thing?

Brian - K6BRN  (AKA Mr. Nosey A**)


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KM6NFF
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Posts: 112




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« Reply #56 on: November 09, 2017, 07:08:48 PM »

Good Idea
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HAMSTUDY
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Posts: 419




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« Reply #57 on: November 09, 2017, 10:12:07 PM »

Robert (KM6NEF):

Suggest you just go out and get 100 feet of connectorized Times Microwave LMR-400 Ultraflex or its equivalent for $130+tax and be done with it.

+1 for Times Microwave LMR-400 UltraFlex
+1 also for N connectors professionally installed ("connectorized" as Brian says)
You can use UHF to N adapters on your radio and antenna (as/if needed); the adapters will add negligible loss and will protect the connectors built into the radio and antenna.
https://www.frys.com/search?search_type=regular&sqxts=1&cat=&query_string=n+to+uhf+connector&nearbyStoreName=false
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HAMSTUDY
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Posts: 419




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« Reply #58 on: November 09, 2017, 10:25:30 PM »

BTW Robert, in case you are still headed for a Comet CHA250B, I think Brian might also be a Comet CHA250B user.
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KM1H
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Posts: 2443




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« Reply #59 on: November 10, 2017, 11:58:47 AM »

Quote
Think of him as a Gunny Sargent - rather than tell him he's wrong, ask "why" - he's got plenty of experience and opinions.  You might learn something, too.  But at least you'll have some input to consider.

Actually a retired USN CWO4 which is several steps above a Master Chief which I had to attain along the way.

Remember that the Chiefs really run the navy as does a Master Gunny in the USMC Grin

BTW, I qualified for Mensa three times; grammar, HS, and the USN; and Wayne Green, who I knew since HS encouraged me to join.

However I had too many enjoyable interests to waste time with a bunch of self centered eggheads Roll Eyes
Girls. Drag and circle track racing, Hot Rods, Custom Cars, Muscle Cars, Antique Vehicles, Girls, Hunting and competition black powder shooting, Competition rifle and pistol shooting, Girls, which are all in addition to a wide range of ham interests since 1955

Carl
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