"Great Quality" RG6 coax

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by NM7G, Nov 24, 2020.

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  1. NM7G

    NM7G Ham Member QRZ Page

    Has anyone experience with or can recommend GQ brand coax? I found some in a 25-foot assembly in a Fred Meyer (Kroger) store with Type F connectors. I was totally unfamiliar with the brand.

    Printed on the coax jacket is "RG6U QUAD SHIELD 18AWG 75*C CATV 3.0 GHZ"
    ("*" is actually the degree symbol)

    A tag on the assembly reads: "BS-55 SATELLITE 25FT RG6 QUADSHIELD WEATHERPROOF COAX
    FOR ALL OUTDOOR AND INDOOR USE

    Specifications: 75 Ohm RG-6/U Quad AWM professional F cables. Weatherproof o-ring silicone compound sealed connectors. AWG 18 solid copper clad steel center. Double aluminum foil shield plus double tinned-copper braid shield. CATV 3.0 GHz.
    Purpose: Suitable for DSS, C/Ku satellite installations."

    I assume C/Ku refers to bands C and Ku, but saying its suitable to 3.0 GHz isn't like attenuation data. Is it good for UHF, junk, or something in between. I lack gear to test it above 150 MHz.
     
  2. AC0GV

    AC0GV Ham Member QRZ Page

    What are you going to use it for? It is made for TV reception, not ham radio transmitting. I use RG-6 for my short wave receiver and it works fine.
    If used for transmitting the SWR will be up a bit but you may get by, better to get a 50 ohm like RG8X .
     
    SM6CJB likes this.
  3. NM7G

    NM7G Ham Member QRZ Page

    I was looking for useful info about it.

    It should work just fine for ham radio if the connectors were replaced, as long as TX power is appropriate. It is probably as good as most RG-59, which well matches a half-wave dipole. But, no, I don't plan to replace my Belden 9913.
     
    K0UO likes this.
  4. KB1CKT

    KB1CKT Ham Member QRZ Page

    I'm dubious of the online calculators, but
    https://www.qsl.net/co8tw/Coax_Calculator.htm
    shows 1.5dB of loss at 30MHz vs 0.7dB for 9913 for 100' runs with 1:1 SWR. When does loss reach the threshold of "too much"? All of us is different. Short runs this is clearly ok, long runs, maybe loss is ok. RX antennas on HF bands often are ok with several dB of loss as the RX antenna makes up for it. Now for TX... maybe a different story.

    Home Depot and Lowes should have 500' spools for under $60 or so. But you'll need to buy their coax crimping kit, and a pair of cutters rated for CCS (what is in the Southwire kit is not sufficient for 18g copper clad steel), and then compression F's. But then you'll have "lots" of coax and connectors for around $120 or so.

    At the moment I have about 500' of this stuff feeding my inverted L on 160m. Running the math I'm losing maybe 0.5dB with a slight mismatch. Well worth it as my antenna is almost 500' from my house! and didn't cost that much. But while the coax can handle "lots" of power and carry 3GHz... I sure wouldn't use more than a few feet at VHF and up, clearly the loss is up there.

    https://owenduffy.net/transmissionline/RG6/index.htm
    This indicates some high power level, which I'm not sure about... seems wrong to run an amateur's kW through the stuff. Just such a thin wire! But 100W? I don't see why not, it'll handle it. [Not sure on the folding back of the foil on making connectors, first I've seen of that, I need to look into that, as I did not and that leaves me wondering now.]
     
  5. KP4SX

    KP4SX Premium Subscriber QRZ Page

    Nothing wrong with RG-6 but I wouldn't expect a Kroger store to have the really good stuff. :rolleyes:
     
    AK5B and K0UO like this.
  6. SPEEDSKATER

    SPEEDSKATER QRZ Member

    Jim Brown, K9YC wrote:

    Repeating my earlier comment, which is the most important one -- RG-numbers have not been a spec for half a century. They are a generic descriptor, telling us Radio Frequency Characteristic Impedance and approximate outside diameter, and nothing more. Rather, we should be specifying (or talking about) a particular part number from a particular manufacturer. My last print copy of Belden's catalog is probably 15 years old. It lists fifty two RG59 cables, sixty four RG6s, eighteen RG8s, and thirty two RG11s.
    Contemporary MIL specs use a very different numbering system.

    73, Jim K9YC
     
  7. KA9JLM

    KA9JLM Ham Member QRZ Page

    I use that type all of the time, It is good stuff.

    I put BNC connectors on it and normally operate UHF running up to 50 watts, No problem.

    At 450 mHz loss is not all that bad.

    Just forget that it is 75 Ohm coax and use it. I would keep power under 100 Watts, HF-UHF.

    A BNC is more reliable than a F.
     
    AK5B, K0UO and KU3X like this.
  8. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    From Duffy's information, RG6 should be usable up to 500 W with SWR < 2:1 on HF. I recently started using RG6 and bought what looked like a good deal on Amazon. But it wasn't.

    The problem with my purchase of cheap RG6 was inadequate copper cladding thickness on the steel center conductor. This causes considerable loss on HF especially on the lower bands. I use a good brand (Commscope) RG6 now. It has proper cladding and is usable for all HF. It has more loss on 160m but not enough to be concerned about for my purposes.

    (Most readily available RG6 has a center conductor of copper clad steel rather than all copper. The quality brands will show attenuation specifications down to 5 or 10 MHz.)

    https://forums.qrz.com/index.php?threads/my-cheap-coax-is-junk-but-why.703069/page-5#post-5456551

    I've never heard of the brand the OP mentioned, GQ Great Quality. In the absence of more information I would assume it's NOT good quality. Buy from a known good cable manufacturer that publishes specifications.
     
    Last edited: Nov 24, 2020
    AK5B likes this.
  9. KA9JLM

    KA9JLM Ham Member QRZ Page

    I remember that. That is what happens when you buy some bad coax, For a cheap price.

    Much of what I use is used for Sat Dish Installs. A roll falls out of the Dish Installers truck when he stops by. :oops:

    The BNC connectors cost more than the coax. They just don't fall off the truck like a roll of coax does. :( But F connectors do. :)
     
    AK5B likes this.
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    One problem is the CATV/Satellite RG6 Quad Shield cable is rarely specified for use below VHF, as the application doesn't require that. It can carry DC through it to power active preamps/mixers in DBS dish antennas, but that's DC and low current; the RF is all at VHF+ through SHF.

    So...I've found some of it does have very, very thin copper coating on the center conductor which can make it more lossy at 160 meters than it is at 2 meters! Just the opposite of the way we normally think about cable loss.

    Other than that disclaimer, I've used RG6 4x-shield TV cable all over the place for many years and at VHF-UHF it works very well and seems to handle TX power fine.

    M2 uses it for baluns on VHF beams rated "legal limit" power (with type F connectors!) and I have a few of those beams, have used them at about 1 kW PEP RF output, and nothing ever failed. If there's a weakness in F connectors, it's likely the female, not the male, that creates the weakness. The M2 F females on their T-match blocks do look different from what's found in inexpensive TV hardware.
     

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