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    Coax Length Issues

    A little update on my new antenna setup from before

    (For those who need context, here's my post about it: https://forums.wtfda.org/forum/dx-equipment/183-new-antenna-setup )

    The antenna (Stellar Yagi) is working fine, though about 2 weeks ago a freak windstorm broke my mast in half and left the yagi hanging with the lower segment. fortunately I was able to reattach the two pieces back with reinforced nails, albeit now it is about half a foot less in height. Now the signals still come in nice and solid, however, one thing i have noticed is that before when I had the yagi close to my window at the front of the house, all I used was a 15 foot old TV coax cable to hook it up to the SDR. Now that its in the backyard, I used my 50 ft. RG-8 coax cable for my 20 meter dipole to reach the yagi.

    Since then, the usual stations that still sound pretty strong have a hard time to decode its RDS, if it even does at all. Sometime ago I was introduced to the concept of RF loss with added coax, but I'm wondering if this also affects RDS data as it travels from the antenna to receiver. If so, I may have to consider shortening my coax. As of now the 50ft PL-259 coax is also hooked up to the old TV coax to make the connection fit, making the total length of coax to be about 65 ft. in total length. I may decide to remove the TV coax and acquire a PL259 to TV coax adaptor to just have it only use the 50ft coax only.

    Has anyone noticed these sorts of decoding issues or signal loss dilemmas when using long pieces of coax?
    -SkyWaveDXBird (Mat)

    DM04XN
    High Desert in Sunny Southern California..

    Record FM DX: WBVM Tampa, FL - 90.5 FM [2,130 miles]
    Record AM DX: HLCA Dangjin, KR [5,989 miles]
    Record HAM Contact: BD9ATY Xian, CN (10 meter FT8) [6,792 miles]

    Current Setup:
    Stellar Labs 30-2640 4-Element Yagi
    MLA-30+ Active Magnetic Loop (with 1/4 diameter copper pipe loop mod)
    Homemade 20m/10m fan wire dipoles
    SDRPlay RSP1A

    https://skywavebirddx.neocities.org/

    "Keep your eyes on the skies..."

    #2
    Mat, your RG-8 coax has an impedance of 50 ohms whereas the antenna balun, and your 15 feet of TV coax both have an impedance of 75 ohms, so you have an impedamce mismatch at both ends of the RG-8. I wouldn't think it woud make a big difference, but you definaitely would be much better off using some quality RG-6, 75 ohm coax from the SDR to the antenna.

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