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Re: A question about 75 Ohm connectors



At 03:02 PM 2/12/2003 -0600, Jon Ogden wrote:
>on 2/12/03 10:05 AM, Estes Wayne-W10191 at W10191@motorola.com wrote:
>
>> It seems to work okay, except the shield on my cheap RG-59 cable is not
very
>> robust.  On two occasions a BNC connector has come apart when moving the
>> portable antenna, dragging a long piece of coax.  The shield strands all
broke
>> under tension.  Now I have a strain relief on the cable.  Also, I didn't
screw
>> the BNC connector as tightly on the replacement cable.  I think I
weakened the
>> shield strands on the first cable by clamping them too tightly in the BNC
>> connector.  
>
>I can't figure out why RG-59 is looked to as the "small" cable of choice for
>75 Ohm uses.  RG-6 is a far better cable.  I learned this last summer when I
>had my DSS system installed.  The RG-59 cables in the house that worked fine
>for CATV did NOT work as well for DSS.  I replaced everything in the house
>with RG-6 and high quality "snap-on" F connectors (like the pros use) and
>now have much better signal strengths to the dish.  RG-6 has a much better
>shield and is just a better cable.
>
>I best most guys using the AIDC converters use RG-59 as well.  Again, I'd
>recommend RG-6 here also.
>
>73,
>
>Jon
>NA9D

Good point Jon.  Having been a C-band satellite TV dealer, I knew that RG-6
was superior to RG-59.  Another fact that is little known is that at 1450
MHz RG-6 has about 6-dB lower loss per 100-foot length (and that is why
satellite-TV systems use it).  But equally important it seems to have
denser shield braid for more reliable connections.  Of course at the 144
MHz IF for 2.4 GHz downconvertors the loss figure is less important.

Ed - AL7EB


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