SWR new antenna

still not happy no. the crt 6900 is only 15watts and the other rig i have (anytone 6666) is 45 watts so my swr could go up. not tried it yet though. Im not the only one thats had trouble look here 
https://www.tapatalk.com/groups/copythat/sirio-megawatt-4000-t15472-s10.html

But it shouldn't alter whatever radio is connected.
SWR is what is reflected back down the coax to the radio and only caused by the antenna setup.
As we have been saying all along the radio and power won't alter the swr well it shouldn't.

bill53uk wrote:

still not happy no. the crt 6900 is only 15watts and the other rig i have (anytone 6666) is 45 watts so my swr could go up. not tried it yet though. Im not the only one thats had trouble look here 
https://www.tapatalk.com/groups/copythat/sirio-megawatt-4000-t15472-s10.html

my 6900 is 35 to 40 watts so why is yours only 15 watts ? an swr of 1.5 is spot on if that's what you can get it down to ... have you tried it out yet did you get good copies ?

Bit late to this. Think I mentioned on another thread previously about when increasing power the SWR can rise and why, but might be dreaming or at least I can't find it. In short it can rise if there is something wrong with the antenna system (and I don't mean just length), e.g. connections, feeder, ground, or it interacting with something close by.

My SWR rises with increased power on 12m and 17m because of interaction between other elements primarily, plus other junk in the loft. 10m, 11m, 12m elements are so physically close, as are 15m and 17m (layout pic on QRZ), there is little I can do about it. But at the small power levels I am using I am not fussed, and all it works well enough.

Quick vid. Sorry it's a bit blurry, was rushing and my close up vision is getting worse by the day



Might be a bit late now, but if your tuning your mobile twig and you're out in the open with no large metal nearby that it might interact with, and SWR is rising when you turn your power up, I would seriously check your connections and feeder cable.


BASS 666 Gary, my 6900 is currently set to 21 watts max on SSB. Think output depends on rig release version, if it's set up for fully export, or in my case if someone (me) has been twiddling.

Thanks for taking the time to make and post a video Neal. Awesome stuff as always.


Let's not forget that most cheap SWR meters work with a simple 'strip-line' which is not only very frequency dependent but also this strip-line is usually not isolated/shielded from the actual analogue meter. Once you go up in power or even frequency there will be more mutual coupling or RF leakage from the RF carrying strip-line to the circuitry and coil of the meter obviously upsetting readings.

On more expensive meters that utilise a strip-line it is completely isolated from the metering circuit with metal shielding to prevent ambiguous readings.

On yet even more expensive meters there will be a different method of measurement rather than a strip-line such as a tandem match, bruene bridge or similar utilising ferrite materials to provide better measurements across a wide range of frequencies and power levels. There may also be more circuitry to prevent measurement errors, PEP functions, etc. Some use a resistive tap line for sampling and read direct through a semiconductor device which can then output to further analogue circuitry to an analogue meter or even an embedded microprocessor system to a digital display.


I know all this 'nonsense' because I modified my simple strip-line Zetagi SWR meter to a tandem match to provide frequency dependent readings as well as additional circuitry for error correction and PEP hold measurements.

(I know, I said I'd post details of this homebrew affair but currently it's apart to fit in my newly built/being built ATU!)


Simply put, you can either fork out for a very expensive SWR meter, (some do and even have a collection of them!!), or sensibly utilise what you have.

On a cheap meter you'd use a lower power ensuring you calibrate your forward setting and tune for best SWR. Don't bother trying to go for the fabled 1:1 SWR reading just try and make sure you're reading less than 2, (90% efficiency!), or a bit lower than that. Even 1.5 is a 96% efficiency!


SWR and tuning an antenna.....can be as simple as you like or flipping complicated.


(I won't even get into how field strength readings can be better than simple SWR processes, the ambiguous 50 ohm impedance or other matters. )


All the best,
Victor

I have ordered a new good value swr meter and i am waiting for delivery. I am sorry that I said my rig was only 15watts, I have investigated further and found that it is in fact 40watts am/fm not 15w as i said in earlier

Could try a Matcher for the SWR.  Seems to work for me.  I use a Zetagi combined SWR and Matcher meter.  Handy bit of kit.  Just a suggestion.

Regards, Ant.  (zodian01)

bill53uk wrote:

I have ordered a new good value swr meter and i am waiting for delivery. I am sorry that I said my rig was only 15watts, I have investigated further and found that it is in fact 40watts am/fm not 15w as i said in earlier

if you are using the built in swr meter it is good enough .. i have a very expensive meter and my built in meter is very close to it in measurement ..

Hi did this get sorted, I've not read through all the comments, but did anyone mention the position of the mag mount ideally being central on the vehicle and also making sure that all doors are closed on the car when adjusting swr, just a thought.

hi all sorry it been a long time since last came on, I have got the swr down to 1.2 on 1 and 1.3 on 40 and thats how far ive got. you have been a great help many thanks lads

Glad you got it sorted out.

it been very frustrating at times. because my car has half sun roof i have to put the antenna further back. I landed taking about 2.5inches off the antenna. but thanks for all your help and ideas. 73.s charlie tango 3036.

That's a more than acceptable SWR well done I hope you enjoy making many contacts.

73's Gary.