CB power
09-12-2007, 07:06 PM
#251
Guest
Posts: n/a
Re: CB power
If the impedances are matched on the antenna, coax and connectors, the
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
09-12-2007, 07:06 PM
#252
Guest
Posts: n/a
Re: CB power
If the impedances are matched on the antenna, coax and connectors, the
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
09-12-2007, 07:06 PM
#253
Guest
Posts: n/a
Re: CB power
If the impedances are matched on the antenna, coax and connectors, the
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
length of the coax is insignificant. Cutting antenna coax to a specific
length to match wavelength in an otherwise matched system is an old
wives tale. Really old.
tw
L. Ron Waddle wrote:
SNIP
> The biggest cause of high SWR's is the fact that typically other parts
> of the transmission chain are radiating or are of a length that is
> chopping up your waves as they head for the tip of the antenna. Thus if
> your coax is not shielded with the shielding grounded properly at both
> ends, your coax length should be a half-wave or quarter-wave in length.
> For 11 meter band (CB radio), that's 8.25 feet if you want a quarter
> wave coax. sNIP
09-12-2007, 07:07 PM
#254
Guest
Posts: n/a
Re: CB power
L. Ron Waddle wrote:
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-12-2007, 07:07 PM
#255
Guest
Posts: n/a
Re: CB power
L. Ron Waddle wrote:
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-12-2007, 07:07 PM
#256
Guest
Posts: n/a
Re: CB power
L. Ron Waddle wrote:
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-12-2007, 07:07 PM
#257
Guest
Posts: n/a
Re: CB power
L. Ron Waddle wrote:
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
If the shielding on your coax is not grounded to a hard
> ground at both ends, your coax becomes an antenna,
If this is the case, then why are antenna's electrically isolated from
the mounting brackets with a nylon bushing or rubber washer? Mag mounts
even have the magnet slightly lower than the metal cup so it can't
ground out and it's covered with mylar.
You have my curiosity up with your 'active shield' vs passive (one end
grounded) shield and mount setup I see.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
09-12-2007, 07:08 PM
#258
Guest
Posts: n/a
Re: CB power
I see that you are stating cut to length if not properly grounded.
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
09-12-2007, 07:08 PM
#259
Guest
Posts: n/a
Re: CB power
I see that you are stating cut to length if not properly grounded.
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
09-12-2007, 07:08 PM
#260
Guest
Posts: n/a
Re: CB power
I see that you are stating cut to length if not properly grounded.
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
tw
twaldron wrote:
> If the impedances are matched on the antenna, coax and connectors, the
> length of the coax is insignificant. Cutting antenna coax to a specific
> length to match wavelength in an otherwise matched system is an old
> wives tale. Really old.
>
> tw
>
>
> L. Ron Waddle wrote:
> SNIP
>
>> The biggest cause of high SWR's is the fact that typically other parts
>> of the transmission chain are radiating or are of a length that is
>> chopping up your waves as they head for the tip of the antenna. Thus
>> if your coax is not shielded with the shielding grounded properly at
>> both ends, your coax length should be a half-wave or quarter-wave in
>> length. For 11 meter band (CB radio), that's 8.25 feet if you want a
>> quarter wave coax. sNIP
