Hi Tim, Thanks for doing the followup. If I had a G5RV that was already installed, I would ditch the balun and coax and splice in 300 Ω ladder line to the house, then a 1:1 current balun and short coax to an external tuner and radio. You and the family stay safe. 73 WJ3U
@acestudioscouk-Ace-G0ACE
2 жыл бұрын
The detailed research presented very well here is both interesting and useful. Thanks for busting some myths Tim!
@timg5tm941
2 жыл бұрын
Thanks!
@g0fvt
2 жыл бұрын
FWIW I have tried doublets in a few scenarios, and the extreme cases can be even more dramatic particularly if your "doublet" gets close to resonance on any band. Sometimes if you have a capable tuner it is just too tempting to operate on bands where you can get a match without thinking of the stress the feeder is under. IE a 40m dipole, and in my case only about 30m of feeder dragged out of the junk box in the car. RG58 as bad as it is gets about 80% of the power to the antenna assuming a 1.5:1 SWR. Bliss, it works just great. When nothing is going on creep on to 20m, antenna is resonant as 2 halfwaves so impedance is somewhere in the region of 5000 ohms, losses go through the roof, over 94% of the power lost, 10m is even worse! Took antenna down and replaced feeder with proper open wire, obviously much the same on 40m but ridiculously better on those harmonics where it was previously useless. True open wire with wide spacing and reasonable cross section conductors is phenomenally low loss, though later that did get replaced by easy to handle 450 ohm. I know this is a bit of an extreme instance but highlights your point, with low SWR on HF modest lengths of RG58 are usually fine. Well done for creating the tables. Another factor of course is that the mismatches mean you need to derate the power handling of the cable..... into a good match quality RG58 is good for about 1kW average on HF... Good work Tim 73
@timg5tm941
2 жыл бұрын
Some great points there thank you!
@AmateurRadioUK
2 жыл бұрын
Good analysis Tim. I agree. Run the ladder line direct to the tuner. Coax is fine if you can have a remote tuner outside (connected directly to the antenna or the ladder line). As for MFJ, I like the somewhat agnostic, diplomatic comments! Personally I've found most of their kit to be ok but what I will say is that many of their "balanced" outputs from their tuners just have a 4:1 balun inside.
@timg5tm941
2 жыл бұрын
Yes indeed MFJ is marmite!
@stevegordon2869
6 ай бұрын
Have used ladder line to tuner and g5rv. The main thing I find is the lobes and nulls are deep. At 102 ft long on 10 meters better with a99 vertical. Some signals the same on g5rv and a 99 some almost nothing. And good signal on Antron 99.
@americaswayout4489
2 жыл бұрын
If you start with the idea ALL antennas work, with some working better than others, a G5RV as a multiband antenna may suit someone's purposes but my experience is the G5RV is and was actually a 20-meter antenna designed to get a certain radiation pattern with a vertical aspect to that radiation. just making it a doublet mixing coax to the feedline and using it as an all-band antenna force-feeding it with a tuner in my view it loses its design purpose. I could never get enough height for the feedline to come straight down to meet the designed installation. I just ended up putting a doublet with each side being just under 150 feet, feeding it with 100 feet of 450-ohm feedline. Strangely it was natively resonating above 12 megs all the way to 6 meters. I did have a heavy 4 balun and about 30 feet of old rRG8. It loaded well everywhere except 75 meters. I have since come to believe the very low SWR was the old RG8 was very lossy giving me a false low SWR reading. I suspect the same would be true if RG58 was used with a long length. SWR is read differently with lossy coax. A doublet is the better all-band antenna with a tuner in my view.
@timg5tm941
2 жыл бұрын
Totally agree!
@MrGohunter
2 жыл бұрын
Hi Tim, great analysis. However, if you bring ladder line all the way into the shack, you’ll get much more RF floating around in the shack, so pretty sure to fail the RF field exposure regulations. Therefore, I think ladder line to just outside the shack and a hefty balun with a short coax run internally is better. Especially if you also add some toroidal RF chokes on the coax. Keep up the good work.
@timg5tm941
2 жыл бұрын
It can be an issue yes. I might have a look at the extra loss (if anything much) going the external Balun route compared with straight to tuner 73
@99corncob
2 жыл бұрын
If you run ladder line directly to your tuner it becomes impossible to add lightning protection to the feed line. With some a mount of coax at the end you can use a normal lightning arrestor before bringing it into the shack.
@DonDegidio
2 жыл бұрын
Hi Tim, Thanks for the followup. If I had a G5RV already installed, I would ditch the balun and coax and splice in some 300 Ω ladder line. Run that to the house and connect to a 1:1 current balun then a short run of good coax to an external tuner then the radio. You and the family stay safe. 73 WJ3U
@timg5tm941
2 жыл бұрын
Great points Don and hope all are well with you , thank you 73
@tombaffa9374
2 жыл бұрын
Very valuable information! Thanks
@timg5tm941
2 жыл бұрын
Thanks!
@douggrissom3065
2 жыл бұрын
I would like to know your opinion of the ZS6BKW antenna. If you are not familiar with it, it is a computer optimized G5RV. It is somewhat shorter than the G5RV and will more easily fit in a small garden. There is even a smaller version called the G0GSF that would fit in a very small garden.
@timg5tm941
2 жыл бұрын
It works well so people say. My only issue is that if you have a small garden why use a 94 foot antenna for 40 and up, when if you feed it entirely with 450 ohm you can easily tune 80 and 60 too.
@marklowe7431
2 жыл бұрын
I just follow a simple rule now. It the VF is
@timg5tm941
2 жыл бұрын
Good points
@basiedp
2 жыл бұрын
Hi. I have a g5rv now for about 15years. Swr low at 1.1 and high at 1.7. 300ohm line. Rg58. All at 110 deg apex, 45deg angle and feedline at centre between 2 radials. Now my coax screen is most dense wind i could find. Cant see through screen. No tuner...BUT it took about 3months to finetune this antenna. Its not a field day antenna. Nice vid thanks. Basie zr2ba.
@timg5tm941
2 жыл бұрын
Thank you!
@greyhound0z
3 ай бұрын
i a great video btw, im just getting into ham radio and just passed my foundation M7GKI i have a full length g5rv to install but it says i need 45 or 90ft of coax so does that mean 45 for a half size and 90ft for a full size?? hanks
@timg5tm941
2 ай бұрын
The coax length may have some influence providing a low enough SWR for all bands to be tuned. Don't get too hung up on that. Use the length you need to operate and go from there.
@Allthingsradio
2 жыл бұрын
Hi Tim I always always use low loss coax it's a no brainer My friend and to all those who think different take note from people like Tim and myself about this
@timg5tm941
2 жыл бұрын
Agree 100%
@johnnorth9355
2 жыл бұрын
213 on all of my long runs - but pain in the neck for tight corners !
@timg5tm941
2 жыл бұрын
Yes it is lol
@Allthingsradio
2 жыл бұрын
Forgot to say I run a g5 half wave amongst my other antenna and have had great results from it and I use RG 213 about 15ft long from the ladder line
@G3PWP
2 жыл бұрын
This is my opinion only .......yes yes and yes I love di poles the secret is to ground everything rg213 compression plugs Rg8 x is also excellent but youre power limit is lower make sure you buy guenuine RG213 or LMR 400 or URM 67 all fabulous quality coax but I use RG8x in the shack upto 100 watts...An 8ft grouind rod is far more effective than a 4 foot ground rod ( 5/8 dia. 4 foot Length x 2 plus brass jointing connenctor if youre ground is poor i.e. builders rubble or sandy and dry which is normally close to youre house remember like Tesco say " every little helps" lol My Di-pole is 100ft approx 75ohm ladder feed then ive ground it to earth at 75 ladder to SO239 connection then in the shack all equipment and I find using old vintage LPF I picked up from fleebay also help with recieve as well TX RFi it really pulls the noise down as im in a built up swamped with broadband users Cheers TIM and all viewers
@timg5tm941
2 жыл бұрын
Good points 73
@itsonlyme9938
2 жыл бұрын
Hi Tim I was using 40ft of rg58 and changed to rg213 on my RX loop and on 10m a local signal was up by 3db .
@timg5tm941
2 жыл бұрын
Just shows 👍
@harveypiper3268
2 жыл бұрын
Thanks Tim! Great presentation 73 K5NR
@timg5tm941
2 жыл бұрын
Thank you Harvey! 73
@paulsengupta971
2 жыл бұрын
I can't help thinking that much of the loss is due to an impedance mismatch. Could you perhaps model both the G5RV and the Doublet/Coax combination with various 1:1, 1:2, 1:4, 1:9 and perhaps even 49:1 transformers? See how that then affects the various bands.
@timg5tm941
2 жыл бұрын
1:1 is usually best as it maintains tuneable impedances. 49:1 should only be used for EFHW where 2k to 4k ohms are typically at the feedpoint.
@donalfinn4205
2 жыл бұрын
Very interesting but it would have been nice to be able to compare all four on the one diagram. I was trying to remember the figures for rg 58!👍☘️
@timg5tm941
2 жыл бұрын
Fair point
@paulhastings3109
2 жыл бұрын
what about S&P I might have the worng coax
@xprcloud
2 жыл бұрын
Abit Missleading , coax losses becomes VERY significant when there is SWR involved, which is the case in most circumstances for g5rv, best is use a bulun and tuner as close to shack as possible, have the ladder lines carry most of the length as balanced ladder/window line has the lowest losses even lower than most expensive coax
@timg5tm941
2 жыл бұрын
And you watched the video??
@onemorething100
2 жыл бұрын
Hello. I have a question that is a bit off topic. I just got my 7300 this weekend. I only have a tech license at this point so I was only concerned with receiving signals. I put up a receive only wire antenna and surprisingly it worked very well on all open bands. When I do put up a TX/RX antenna, that is maybe 1 or 2 band specific, will I still receive on the remaining bands? I don't plan on transmitting until the 10 meter opens so most of my time is spent listening. If that's the case should I just leave my receive antenna up? I don't want to lose the ability to listen on other bands. Thank You.
@paulsengupta971
2 жыл бұрын
It depends on the matching. It can be an issue on receive. My end fed wire antenna doesn't receive at all well on 20m until I hit the "tune" button and get my tuner to transmit and tune itself, then reception is great.
@timg5tm941
2 жыл бұрын
Yes - Paul has summed this up well below 73
@hamshackleton
2 жыл бұрын
I was hoping you would compare Westflex with other cables.
@timg5tm941
2 жыл бұрын
Ah right
@brian.7966
2 жыл бұрын
always use the best you can buy, less like of to much loss. you get what you buy.
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