RF Co-axial cable for audio interconnects.

felixscerri · « **on:** 8 Jun 2016, 06:59 am »

G'day all, this is an interesting one as today I received some audio interconnects that I ordered mostly on a whim which are made of RG58U, a shielded coaxial cable designed essentially for RF transmission line use.

As I am a Ham Radio operator myself, (callsign vk4fuq) I am very familiar with RG58U for RF applications, but how does it work for use as an audio interconnect? Very well, with excellent braid shielding and low capacitance, although I have seen lower capacitance shielded cable for audio use. Essentially though RG58U coaxial cable makes a very good interconnect for audio use. Regards, Felix.

Folsom · « **Reply #1 on:** 8 Jun 2016, 07:18 am »

My experience is it sounds bad.

felixscerri · « **Reply #2 on:** 8 Jun 2016, 07:23 am »

G'day mate, that's interesting as mine sound just fine. Regards, Felix.

Wayner · « **Reply #3 on:** 8 Jun 2016, 11:45 am »

I've made many pairs with Coleman RG59/U. A 1 meter cable with RCA plugs measures about 54pf, which is pretty awesome. This cable has a 22awg center, copper conductor and a 95% copper braided shield. Very flexible for being a coax connector.

Sounds great.

'ner

srb · « **Reply #4 on:** 8 Jun 2016, 12:13 pm »

RG59/U is a ~ 75 ohm cable (vs. RG58/U ~ 50 ohm) which also makes it more suitable to be used as an S/PDIF digital cable if desired. It also has ~ 25% less capacitance per foot than RG58/U.

Steve

Wayne1 · « **Reply #5 on:** 8 Jun 2016, 12:33 pm »

Belden 89259 is a very popular RG59/U cable used for interconnects.

From Blue Jeans Cable: Belden 89259 is a plenum-rated RG-59 type video coax, with a stranded (7x30) centre conductor and bare copper braid shield, and with FEP (Teflon) dielectric and outer jacket .

Both Belden 1694 and 1695 are very, very good when used for digital interconnects. 1695 is the same as 1694 but uses Teflon dielectric.

Speedskater · « **Reply #6 on:** 8 Jun 2016, 12:40 pm »

The RG cable system is now about 3/4 of a century old. It only defines the cable's Radio Frequency Characteristic Impedance and diameters. At one time Belden Cable listed about 40 different RG59 cables. Different cables were optimized for different parameters.
So some RG59 cables are good for audio while others are not. The ones with a heavy braided shield are best.

felixscerri · « **Reply #7 on:** 9 Jun 2016, 12:06 am »

G'day all, thanks for all comments. This is actually getting to be quite interesting as the sound of these RG58U interconnects is quite different to my usual pair, with a clarity and a crispness that my usual pair don't possess.

If anything my usual pair sound clean but soft/gentle. I think that I prefer the sound of these RG58U interconnects especially feeding from my Shure M97xE! Their main claim to fame is superior hum rejection interestingly enough, and that is actually quite good, but apart from anything else their sound is different. Especially in phono interconnect applications I've always considered cable capacitance as being of primary importance and maybe there are other cable parameters of equal importance as well! Regards, Felix.