Can the swr be to low?

[King Mudduck]

I tried different mics no change and yes my gain is wide open. :roll: I going to my local tech this weekend i tell him about the things that all of you have posted as i dont have the equipment to check the oms of the coax.
I checked my dead key this weekend and it is less than 1(no swing kit in the radio) watt.I tried to turn the key up but it would not go any higher than that so i think there is something else wrong with the radio.thanks for all the info.

 

[Navionic]

Same situation....

I am using a Uniden PC 78LTW CB with roughly 20' of of RG8X and a 102" steel whip (Distance has been dictated by placement on my whip on the back bumper of my 3/4 extended cab, long bed pickup.) Same thing. Less than 1 on the SWR, but I have excellent transmit power for only running 4 watts I am talking over very nice distances clear as can be.

To the gentlemen that suggested reading 50 ohms on a DMM. You can't read impedance on a typical DMM. It's not simply a DC resistance measurement, it is a measurement of impedance to an AC signal within a certain frequency range. If you put a DMM on a coax, you should read infinity (or very high resistance value) unless your dielectric is faulty and center electrode is touching the shielding.

And I sure wish that people would get away from the myth of length of coax having effect on the performance of a transmitter. Either the coax matches the impedance or it does not. The impedance does not change with length, and velocity factor does not 'factor' into this. The only velocity factor you may concern yourself with is using a Time Domain Reflectometer (TDR) to troubleshoot where in a coax (or other type of cable/conductors) to determine where you may have a short between conductor and shield (bad dielectric), or an open (probably from a flexing coax). In these cases, you are only concerning yourself with velocity factor to match the capacitance of the cable, be it a dielectric or air between two twisted wires in order to provide a correct distance to fault.

Sincerely,
Mark C.
Former Naval Avionics GOD!
Now just a telecommunications monkey flingin poo at faulty load coils.

:blink:

 

[midnight special]

just my 2 cents worth,,,, i had a trc 465 with palomar 100 to a 102 inche whip with radio shack rg8 coax,,, the swr was flat using a mfj 259 from 25 to 29mhz.
but range was only a few miles maybe just a little bit more with altitude. turned out my coax from amp to antenna was acting like dummy load for some reason. i changed it out with belden rg213 and then it was a talker. threw that radio shack stuff away and had no problem since. 73s midnight special

 

[W5LZ]

SWR only deals with the transfer of power from the transmitter to the antenna. It has nothing to do with how any particular antenna radiates, or where that radiated signal goes. A typical dummy load makes for a very nice transfer of power (SWR). That typical dummy load makes for a terrible antenna because of how it radiates, almost nothing radiated (in that regard, SWR means very little about how well an antenna radiates). So a dummy load has a very impractical radiation pattern (small). That "how it radiates" or the radiation pattern determine how 'good' an antenna is in any particular situation. And that radiation pattern is always dependent on propagation, especially at HF. One of the things that say how well an antenna radiates is it's physical length, some lengths are 'better' than others.
- 'Doc

 

[Captain Kilowatt]

Gotta love these seven year old threads being resurrected from the dead. :blink:

 

[n0zna]

cant beat 213,

thats all i use,73 de JW

 

[The Mad Scientist]

hi gentelman, going back to the origonal post about "sounding bad" at close range, i see that is wasen't mentioned if the amplifier was "on" or not.

it could be that the 95t could have had a little front end overload being that close if the amplifier was on.....just a thought.

 

[Peddler]

Well well ... I always thought you needed 500 watts to talk 70 ft ... the truckers used to.

 

[hotrod]

id say its most likely in the radio itself. if talking close up the amp isnt needed
so id turn it off probly overloading the recieve on other radio.if not this
then id say have your dk raised to 3-5 watts all way up.