RG58 vs RG213 Coax

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Goffy
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RG58 vs RG213 Coax

Post by Goffy »

Is the RG213 worth the extra expense? Will it be a dramatic improvement over RG58? I live in a location with poor line of sight so I'm trying to get the best gain I can. Will be using with either a discone or a white stick for listening to mainly 156mhz up to 470mhz
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Re: RG58 vs RG213 Coax

Post by Otter »

What length is your cable run? You can work out the loss from this chart <link>
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Re: RG58 vs RG213 Coax

Post by Mitch »

Goffy wrote: 18 Sep 2019, 23:39 Is the RG213 worth the extra expense? Will it be a dramatic improvement over RG58? ...
Most definitely, especially at UHF. I extended my CB aerial with 20m of RG58 but before I used it I measured a 30% loss (at 27Mhz) through it. And that's at HF, at UHF it's more like a dummy load. I didn't measure the loss with RG213 that I have on a Diamond 2000 but there's only 17m total, on a 30ft pole. Spend the extra, or look for a bargain, they do exist, I got 100m of RG213 for £40 a while back.
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ch25
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Re: RG58 vs RG213 Coax

Post by ch25 »

For example.
@470MHz
20m of RG58 gives 6dB of loss - 1s unit
20m of RG213 gives 3.2dB - 0.5 s unit.
Not worth the effort IMO.
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Re: RG58 vs RG213 Coax

Post by Tigersaw »

For RX only it wont make a jot.
You could change it for satellite CT100 which is cheap and low loss at UHF if you want to experiment
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Re: RG58 vs RG213 Coax

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Otter wrote: 19 Sep 2019, 08:36 What length is your cable run? You can work out the loss from this chart <link>
Around 20 metres. I'll study the charts in that link. Thanks.
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Re: RG58 vs RG213 Coax

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A couple of people have mentioned satellite. I imagine thats great at UHF but I'm not sure how well it will do on vhf marine band.
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ch25
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Re: RG58 vs RG213 Coax

Post by ch25 »

Satellite coax work miracles even on HF. I use it to my RX antennas. Cheap and low loss. Especially when you need hundreds of meters :)
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Re: RG58 vs RG213 Coax

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Cheers Chris thats cheered me up because its also a heck of a lot cheaper to buy the sat stuff. But I had always believed 75ohm cable should never be used with receivers that need a 50ohm cable for reasons of impedence mismatch.
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Re: RG58 vs RG213 Coax

Post by ch25 »

Mismatch loss is marginal when use that cable for RX, TX is different story, but you can use it too for some antennas and power levels.
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Re: RG58 vs RG213 Coax

Post by paulears »

RG213 is chunky, stiff and has a worse attenuation figure than Ct100 or the other satellite stuff. So for receive, CT100 though thinner WILL produce better results on a scanner, despite the mismatch of impedances. The biggest issue is connectors. CT100 works great on F connectors, but is horrible and quite unreliable when you need to fit it to PL259, N types or BNCs. The centre core is thin and brittle, and the screen braid that you need to solder to, or use in the compression glands is thin and breaks almost by breathing. You can have a perfectly sound connection, then plug it in and the weight of the cable is enough to snap the few measly wisps of cheap copper braid, wrecking the connection. All the usual RF connectors that have pins, and not a pressure fit like F types need either crimping (which breaks the centre) or soldering, which often melts the dielectric as it's cheap low temp plastic.

So - you could try an F to BNC, or N or PL259 adaptor - but these are very variable in quality.

So my opinion is the cable itself is low loss and dirt cheap, but incredibly fragile. RG213 is not as good RF wise in terms of losing signal going down the cable, but I've got my antennas on 213, plus other old lengths of lower loss larger diameter cable because it's easy to waterproof. A fragility connection at the top of a pole that wiggles in the wind worries me, and while self-amalgamating tape works wonders CT100 cable is never going to be long life especially as it is a perfect conduit for water getting in if your connections are not 100% solid.

However - as it's pennies not pounds, if you don't mind climbing a ladder every now and then, it can work wonders against cheap rubbish like RG58 at anything higher than 70MHz and a decent length. For me - at VHF and above, 2 or 3 metres of 58 is fine. 10m is really pushing it.
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Re: RG58 vs RG213 Coax

Post by Goffy »

Thanks for all the replies. I decided on WF100 which is the equivalent of CT100 but with a foam inner rather than air - so should avoid the water ingress issues you mention Paul.

Now another question has arisen. While pricing cables and connectors I've seen two radio websites (not sellers just info reference sites) that specifically say avoid SO-239 connectors and go for N-type because the former is no good above 300mhz! But the white sticks all seem to have SO-239. Discones have N type more often. Is that true about the SO-293 being crap? Its a minefield this.
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Re: RG58 vs RG213 Coax

Post by Tigersaw »

Oxygen free pure copper 21 strand cable run either North South or East West with exact 20mm radius bends is best for your speakers.. apparently, but you wont hear any difference if you use cooker cable.

At UHF then N type or BNC is the correct way to go, but SO239 is far from being a crap connector and no-one would notice any difference.

You are researching this too much, especially for a receiver.
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Re: RG58 vs RG213 Coax

Post by Goffy »

Yep i'm overthinking the whole thing. Anyway I've just spotted a Diamond X30 at a discount and its got an N connector. So thats what I'm buying and 35 metres of WF100
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Re: RG58 vs RG213 Coax

Post by Tigersaw »

Goffy wrote: 20 Sep 2019, 16:06 Yep i'm overthinking the whole thing. Anyway I've just spotted a Diamond X30 at a discount and its got an N connector. So thats what I'm buying and 35 metres of WF100
Good call, I have had one of those and it worked well placed low down, has a fairly broad polar pattern
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