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Re: active cb users

PostPosted: Sun Sep 27, 2015 11:44 am
by JGR
BlackKnight_UK wrote:I was considering getting a new base antenna to replace the old one which is still there, and an SSB radio, maybe I should have done that instead of buying a multi handheld.

Antenna first and foremost with everything we do with RF as without a good antenna the item on the other end means nothing, still you can keep saving up and get one eventually. :thumbup:

Re: active cb users

PostPosted: Sun Sep 27, 2015 12:44 pm
by m0lsx
Even on a wavelength a short as 10 meters & legal CB frequencies are at the top end of 10 meters in wavelength. The losses as a result of a combination of very short inefficient antenna combined with a lack of counterpoise is going to bite you.
One thing that may help with a CB handheld is what I do on 4 meters to help with the lack of performance. A counterpoise tail. On 4 meters I use 2 meters of wire connected under a screw.
A hand portable is great for hill topping & with a counterpoise & smallish portable antenna, good distances can be worked from a small ruck sack.

Re: active cb users

PostPosted: Mon Sep 28, 2015 11:13 pm
by auntystatic
Don't forget British CB changed last year to include the use the CEPT frequencies with 12Watt sideband usage, something we have been waiting for, for 30 years, its in the 11 metre band ( top end of 10 metres is for amateur fm and satellite working only :smiles: ) although 27.555MHz usb is outside the band it is recognised as the international calling frequency, when the conditions allow there are lots of people calling on there, more information can be found on the ofcom site http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/research-guidelines-tech-info/interface-requirements/IR_2027.2.pdf

Re: active cb users

PostPosted: Tue Sep 29, 2015 12:25 pm
by m0lsx
auntystatic wrote:Don't forget British CB changed last year to include the use the CEPT frequencies with 12Watt sideband usage, something we have been waiting for, for 30 years, its in the 11 metre band ( top end of 10 metres is for amateur fm and satellite working only :smiles: ) although 27.555MHz usb is outside the band it is recognised as the international calling frequency, when the conditions allow there are lots of people calling on there, more information can be found on the ofcom site http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/research-guidelines-tech-info/interface-requirements/IR_2027.2.pdf


It is not until you get below 27.300 Mhz that it is 11 meters.
The calculation is the speed of a radio wave 300,000 meters per second divided by the frequency in khz.

Re: active cb users

PostPosted: Wed Sep 30, 2015 10:24 am
by BlackKnight_UK
But who is arguing over a few centimeters?

Re: active cb users

PostPosted: Wed Sep 30, 2015 4:22 pm
by Crazylegs
BlackKnight_UK wrote:But who is arguing over a few centimeters?

Yes exactly!

Re: active cb users

PostPosted: Wed Sep 30, 2015 5:34 pm
by m0lsx
BlackKnight_UK wrote:But who is arguing over a few centimeters?


But when it comes to antenna length it is not just a few CM's is it??

Re: active cb users

PostPosted: Wed Sep 30, 2015 9:35 pm
by Alfie
I get a bit of traffic on cb channels busy through the day with mostly truck drivers and other mobiles. i also get local and long distantish chat at night a lot of nights. also get a bit of interference and foreign stations coming in so i have cb all in one bank so i can lock it out whenever. dont forget to program all 80 channels in not just the uk40 and 27.555 MHz (USB).

Re: active cb users

PostPosted: Wed Sep 30, 2015 10:53 pm
by m0lsx
CB is about the only thing I use my old Alinco DJ-X3 for now. I originally brought it to listen to the old scrambled analogue Police transmissions, which it did a great job of resolving. I also used it to listen to the old 31 MHz cordless phones.
But now, if it is used it is simply to scan manually through the CB bands. I also occasionally use one of my base radios on band scans, as I am scanning with the others. And CB is perfect for band scans as it is a small chunk of spectrum. I generally scan 26.5 to 28 in 5khz steps.

Re: active cb users

PostPosted: Thu Oct 01, 2015 10:54 am
by BlackKnight_UK
m0lsx wrote:
BlackKnight_UK wrote:But who is arguing over a few centimeters?


But when it comes to antenna length it is not just a few CM's is it??


I'm fairly certain it doesn't make much difference if you are trying to tune your antenna to cover all legal channels, unless you are going to adjust it for every channel!