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Rx vs tx optimum settings

N

nfsus

Yeah its turned off, touch it
May 9, 2011
486
250
73
47
Arkansas
Using an analyzer, where do you find you get the best tx quality in the swr, joules, resistance, phase ect....? Well should be where the ant is resonant. Let's pretend it is since some dont agree.

Same ant same analyzer, what settings do you find are the best for rx?

I'm seeing that the rx and tx are not the same. I can tune for rx or I can tune for rx and they are not the same across the board. Like 2 ant would be better. Old school and all.

Anyway have yall noticed this as well
 
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I haven't looked into it, but that would explain why my Yaesu has a separate RX antenna jack on the rear, and button on the front.
 
nfsus said:
Using an analyzer, where do you find you get the best tx quality in the swr, joules, resistance, phase ect....? Well should be where the ant is resonant. Let's pretend it is since some dont agree.

Same ant same analyzer, what settings do you find are the best for rx?

I'm seeing that the rx and tx are not the same. I can tune for rx or I can tune for rx and they are not the same across the board. Like 2 ant would be better. Old school and all.

Anyway have yall noticed this as well
Click to expand...

yes

I am not sure what polarity for TX you are using but if vertical, a .64 wavelength will give you the largest single lobe and the strongest signal on the horizon. Anything longer starts a second lobe and anything shorter isn't as efficient. But a .64 wavelength vertical is not the best RX antenna. Generally for RX, the longer the better (more capture area).

If you are talking about analyzer readings, a dummy load is the best TX antenna. All resistive, no reactive, none of the TX power is reflected back - there is no standing wave. Unfortunately, the make poor radiating antennas.

Antennas designed to radiate, generally have some reactance (capacitive/inductive), and when that gets in the mix, as you have observed, R=50 and X=0 are rarely at the same point.
 
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I can take my antenna and atatch it to this magic coil I've made with special unicorn farts and ghost glitter with special nipple clamps........

Yes the coil is real. It's a set of switched matching coils I'm working on. And when I use the dipole that's pretty good number wise I can boost my rx by switching in my coils. It will boost the rx a few units. If I can raise x from single digits to around 50 the rx is stronger.
 
Dr_DX said:
yes

I am not sure what polarity for TX you are using but if vertical, a .64 wavelength will give you the largest single lobe and the strongest signal on the horizon. Anything longer starts a second lobe and anything shorter isn't as efficient. But a .64 wavelength vertical is not the best RX antenna. Generally for RX, the longer the better (more capture area).

If you are talking about analyzer readings, a dummy load is the best TX antenna. All resistive, no reactive, none of the TX power is reflected back - there is no standing wave. Unfortunately, the make poor radiating antennas.

Antennas designed to radiate, generally have some reactance (capacitive/inductive), and when that gets in the mix, as you have observed, R=50 and X=0 are rarely at the same point.
Click to expand...
That is interesting, definitely need to get my long wire up out back now.
 
Shadetree Mechanic said:
definitely need to get my long wire up out back now.
Click to expand...

CHRIS: Darn you buddy!!!! I told you to put up an inverted "L" off that very cool, tilt-over antenna mount years ago when you brought Grandpa's Hammarlund home!!!!
Dang it with ALL that NICE HF Gear ((y):LOL:) you have there, you should have a receiving antenna for them.
You add a very simple little "L" network at the bench (or even just a variable broadcast cap) at the bench to tune it with.
I know you would have fun with it!!!
All the Best
Gary

swl1_ant1_2c.jpg


Very simple little RX "L" network above...or where torrid coil is,replace with an open coil with short clip lead to change taps!!! Does not have to be at great height outside either, just high enough so you can walk under it and not "cloths line" anyone one when everybody's outside. (Even run along that fence at top)
That black super flex 16 ga. antenna wire DX ENG sells is great stuff and almost invisible from like front yard. I have like 400+ft of that stuff running on my lot for different antennas.
Most you can't even see from street 100ft. away(y):LOL:

maxresdefault.jpg

very simple tuner pictured above, works great for any type of random length wire for a receiving antenna to "PEAK" what you're listening to on any given band.(y):)
You don't even need the little tuner, but they do help. That old receiver you have, I believe has one built-in. I think there is a small adjusting cap marked "antenna" on front panel it that does just that!
The little network on the shack side just gives you a little more versatile tuning.
 
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Greg T said:
I haven't looked into it, but that would explain why my Yaesu has a separate RX antenna jack on the rear, and button on the front.
Click to expand...

That port is so that you can use an antenna such as a low noise RX loop or Beveridge antenna that is NOT suitable for transmitting into yet provides a better S/N ratio than your normal TX antenna.
 
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BJ radionut said:
CHRIS: Darn you buddy!!!! I told you to put up an inverted "L" off that very cool, tilt-over antenna mount years ago when you brought Grandpa's Hammarlund home!!!!
Dang it with ALL that NICE HF Gear ((y):LOL:) you have there, you should have a receiving antenna for them.
You add a very simple little "L" network at the bench (or even just a variable broadcast cap) at the bench to tune it with.
I know you would have fun with it!!!
All the Best
Gary

swl1_ant1_2c.jpg


Very simple little RX "L" network above...or where torrid coil is,replace with an open coil with short clip lead to change taps!!! Does not have to be at great height outside either, just high enough so you can walk under it and not "cloths line" anyone one when everybody's outside. (Even run along that fence at top)
That black super flex 16 ga. antenna wire DX ENG sells is great stuff and almost invisible from like front yard. I have like 400+ft of that stuff running on my lot for different antennas.
Most you can't even see from street 100ft. away(y):LOL:

maxresdefault.jpg

very simple tuner pictured above, works great for any type of random length wire for a receiving antenna to "PEAK" what your listen to on any given band.(y):)
You don't even need the little tuner, but they do help. That old receiver you have, I believe has one built-in. I think there is a small adjusting cap marked "antenna" on front panel it that does just that!
The little network on the shack side just gives you a little more versatile tuning.
Click to expand...
I think I even have a new spare tuning control for the Hammerlund in a box of radio parts from my grandfather. Now I gotta find it.
 
Captain Kilowatt said:
That port is so that you can use an antenna such as a low noise RX loop or Beveridge antenna that is NOT suitable for transmitting into yet provides a better S/N ratio than your normal TX antenna.
Click to expand...

Holy cow.
Should have guessed that. Didn't. (n)
Now I understand the two HF antenna ports. :D
Thank you. (y)
 
Riverman said:
Holy cow.
Should have guessed that. Didn't. (n)
Now I understand the two HF antenna ports. :D
Thank you. (y)
Click to expand...


Depends on the radio. Some have regular antenna ports so an external antenna switch is not required. If it is designated as a separate RX antenna port, they usually have a different RF connector such as an RCA type but not necessarily, then it is indeed for RX only. It goes directly to the RX section and is not switched to the TX section at all. My Icom IC-735 had one with RCA connectors. Normally there was a jumper connecting it to the main antenna jack. Pulling the jumper and inserting rx filters allowed me to use the filters without worrying about them being subjected to RF when I transmitted.
 

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