RG58 or RG213

[eswnl]

Hi,

Having decided to put a g5rv outside and running about 15m of coax, I was wondering if RG58 would suffice, being at low frequencies/easier to manage. The coax would be coming out of the eaves and drape across to the g5rv feedpoint. I guess RG58 is lighter than RG213 and so would not put too much strain on the antenna.

[northern35s]

Without doing a little research I don't know what the losses are in 15m of RG58, but at HF frequencies they are minimal. I feed all my antennas at home with RG213, mainly because I can and would like to reduce the loss, however for the length of run I have I doubt I'd notice the difference between RG213 and RG58. It's a different story at VHF and UHF, where RG213 becomes a bit too lossy.

[MrWeetabix]

213 is regarded as better than 58, though at HF, you'll not notice the difference. If you can afford 213, then go for that, a much better buy and can be re-used for VHF/UHF at a later date.

[Jon_D]

The coax would be coming out of the eaves and drape across to the G5rv feedpoint.

Then if this is fed with coax, it is not a G5RV. That antenna is fed with open wire feeder at the feedpoint and the only coax is that which comes from the TX which is THEN attached to the open wire feed; the latter is generally 300 Ohm.
Are you taking about a dipole fed with the coax?

[eswnl]

The coax would be coming out of the eaves and drape across to the G5rv feedpoint.

Then if this is fed with coax, it is not a G5RV. That antenna is fed with open wire feeder at the feedpoint and the only coax is that which comes from the TX which is THEN attached to the open wire feed; the latter is generally 300 Ohm.
Are you taking about a dipole fed with the coax?

Sorry, I meant to say that the coax plugs into the ladderline that hangs from the middle of the antenna.

[Jon_D]

Thanks for that...I didn't mean to be contentious. I was about to advise on velocity factor and ATUs. but needn't now.
Good luck with the G4RV; If you get it on 6 Metres, let us know as i need an antenna for that band.

[g0slq]

213 is regarded as better than 58, though at HF, you'll not notice the difference. If you can afford 213, then go for that, a much better buy and can be re-used for VHF/UHF at a later date.

There used to be a (rough) guide.

RG58 HF
RG213 VHF i.e. 6/4/2m
Westflex 103 UHF
SUHF, i.e. 23cm and up Ecoflex 15 - with an eye-watering cost of £5+ per meter to keep losses to a miimum!

[Captain Lockheed]

Hi,
I guess RG58 is lighter than RG213 and so would not put too much strain on the antenna.

Yep, RG-58 is considerably lighter, so if that's a major issue then go for it.
Just don't go shoving a kilowatt of rtty up it on 10m, RG-58 doesn't like that... apparantly

[Yeti]

213 is regarded as better than 58, though at HF, you'll not notice the difference. If you can afford 213, then go for that, a much better buy and can be re-used for VHF/UHF at a later date.

There used to be a (rough) guide.

RG58 HF
RG213 VHF i.e. 6/4/2m
Westflex 103 UHF
SUHF, i.e. 23cm and up Ecoflex 15 - with an eye-watering cost of £5+ per meter to keep losses to a miimum!

You forgot LDF450

[g0slq]

Ahem

Not forgetting LDF 450 of course for those whacky enough to transmit 2.4Ghz and higher

[eswnl]

Thanks for the replies. I managed to find a website that calculates line losses, so I've decided on the rg58.

Just don't go shoving a kilowatt of rtty up it on 10m, RG-58 doesn't like that... apparantly

So coax has power ratings? Too much power would cause the coax to melt?

[Captain Lockheed]

Thanks for the replies. I managed to find a website that calculates line losses, so I've decided on the rg58.

Just don't go shoving a kilowatt of rtty up it on 10m, RG-58 doesn't like that... apparantly

So coax has power ratings? Too much power would cause the coax to melt?

Said mainly in jest, but yes, all transmission lines have a limit but they are not really relevant to anyone using U.K. limits on HF. With RG-58 it's not an issue until using silly levels of power on higher bands and using 100% duty cycles modes, i.e. 10m and rtty.

[Yeti]

Thanks for the replies. I managed to find a website that calculates line losses, so I've decided on the rg58.

Just don't go shoving a kilowatt of rtty up it on 10m, RG-58 doesn't like that... apparantly

So coax has power ratings? Too much power would cause the coax to melt?

Yes.

[MrWeetabix]

sizzle sizzle

[YB135]

May I draw your attention to this link: http://news.bbc.co.uk/1/hi/sci/tech/8661228.stm

I think this picture was taken when wor bixy' downed the key on his new 10kW burner with very poor coax connected, as you can see from the previous picture that is what happened to the coax. Note on http://news.bbc.co.uk/1/hi/sci/tech/8661228.stm the strong reading from the north east of england, maybe the newcastle region... hmmmm coincidence????