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[RedDevil]

Sorry, Beagle - this is one area where I DO know what I'm talking about, and I can assure you that over this side of the Atlantic (still in the world!) our CBs are - and have always been, if they were legal - FM.

From http://en.wikipedia.org/wiki/CB_radio_in_the_United_Kingdom

"...the preferred option for legalisation was the U.S. 27MHz AM system....The final legalised service was a compromise - a band at 27MHz was allocated but using FM and offset channel frequencies 27.60125 - 27.99125 MHz which were incompatible with the U.S. system.  The channels legalised on 2 November 1981 were on two blocks of frequencies: 40 channels on the 27 MHz band and 20 channels on the 934 MHz band, both of which used FM (frequency modulation) ..... In the 1990s 40 additional frequencies were added, which were ironically the same as the U.S. allocation - but again using FM."

While that covers just the UK, quite a number of other countries use FM for CB as well;  the current one in use here is Europe-wide, I believe - still FM!

Jim

If you're operating in the upper 27 MHz band similar to the US, the factory whips should work...they are supposedly tuned, and I use that term very loosely from how bad the factory whips are, to optimally operate in the band 26.965-27.405 MHz.  Theoretically, the more you go below 26.965 or above 27.405, your SWR will go up as the frequencies go farther away from tuned frequency of the antenna.   When Japan opened up 40 more channels above 27.405, you could still use the same antenna to transmit on, but if you had an antenna tuner, and you planned on using the upper 40 channels, you optimally tuned your antenna for channel 41 for the lowest SWR and then the SWR would increase roughly equal on both sides the farther you got away from channel 41.  Beages is definitely right about kinks and severe bends in the coax cable...that will throw your SWR through the roof and you'll never be able to tune them...

If anyone's interested in some "CB-101", here's a link to a pretty good website:  http://home.att.net/~wizardoz/cbmw/rwpropag.html

Cheers [smiley=xyxthumbs.gif],
Red

[Eqcons]

If you're operating in the upper 27 MHz band similar to the US, the factory whips should work...they are supposedly tuned, and I use that term very loosely from how bad the factory whips are, to optimally operate in the band 26.965-27.405 MHz.  Theoretically, the more you go below 26.965 or above 27.405, your SWR will go up as the frequencies go farther away from tuned frequency of the antenna.   When Japan opened up 40 more channels above 27.405, you could still use the same antenna to transmit on, but if you had an antenna tuner, and you planned on using the upper 40 channels, you optimally tuned your antenna for channel 41 for the lowest SWR and then the SWR would increase roughly equal on both sides the farther you got away from channel 41.  Beages is definitely right about kinks and severe bends in the coax cable...that will throw your SWR through the roof and you'll never be able to tune them...
Just my $.02.
Cheers [smiley=xyxthumbs.gif],
Red

Yes, thanks Red - I know all of that stuff, I was an avid (and illegal!) CB enthusiast here in the early 80s, using AM, FM, 120 channels and SSB.   With boots on to work the skip.  Still have most of my equipment, maybe one of these days it will have antique value!  

My question was really just how much adjustment is there in the antennae from J&M, so that a decent SWR around channel 30 (the one we use most) could be attainable. Just had a nice email from John Lazzeroni at J&M, saying: "I am very sorry ,,, I don't have a positive idea on whether or not those
antennas will work for you ,,,,,

We do not have access to 27mhz FM transceivers ,,,,"

But the FM bit won't matter, of course, so it sounds as if they are worth a try!

Jim

[RedDevil]

Yes, thanks Red - I know all of that stuff, I was an avid (and illegal!) CB enthusiast here in the early 80s, using AM, FM, 120 channels and SSB.   With boots on to work the skip.  Still have most of my equipment, maybe one of these days it will have antique value!  

My question was really just how much adjustment is there in the antennae from J&M, so that a decent SWR around channel 30 (the one we use most) could be attainable. Just had a nice email from John Lazzeroni at J&M, saying: "I am very sorry ,,, I don't have a positive idea on whether or not those
antennas will work for you ,,,,,

We do not have access to 27mhz FM transceivers ,,,,"

But the FM bit won't matter, of course, so it sounds as if they are worth a try!

Jim

When I talked to John Lazzeroni at J&M about tuning the antenna, he told me that to optimally tune it to channel 19 or 20, to unravel about 1-2" of copper wire off of the top.  So I would guess that if you would unravel and cut off about 2-3 inches, you would be closer to channel 30.  As you know, going higher in frequency, you need to make the antenna physically shorter, or at least make the radio think it's physically shorter.   For liability reasons, he had to give you that answer, but you should be good to go if you tune them the way I just mentioned.  Just unravel a little at a time, cut it off and see how it goes.  Remember, you have two antennas to play with to get it right.  
I had a few of those 80 channel CB radios  with some "foot warmers" that I used back in my heavy skip shooting days.[smiley=nervous.gif].  

cheers  [smiley=xyxthumbs.gif],
Red

[Eqcons]

When I talked to John Lazzeroni at J&M about tuning the antenna, he told me that to optimally tune it to channel 19 or 20, to unravel about 1-2" of copper wire off of the top.  So I would guess that if you would unravel and cut off about 2-3 inches, you would be closer to channel 30.  As you know, going higher in frequency, you need to make the antenna physically shorter, or at least make the radio think it's physically shorter.   For liability reasons, he had to give you that answer, but you should be good to go if you tune them the way I just mentioned.  Just unravel a little at a time, cut it off and see how it goes.  Remember, you have two antennas to play with to get it right.  
I had a few of those 80 channel CB radios  with some "foot warmers" that I used back in my heavy skip shooting days.[smiley=nervous.gif].  

cheers  [smiley=xyxthumbs.gif],
Red

Thanks Red.  Worth a try for sure. The BIG problem is going to be the adapters from PL259 down to these little things, so I can plug in my SWR meter....

Jim

[arcticdude]

The parts previously listed from "Radio Crap" will make the meter hookup simple.  Just plug/play.  For those of you with knowledge, we have an 06 and an 07.  (we can't eat, but we can ride.)  The 06 needed about 2" taken off the CB antenna to get great swr readings.  The 07 can't get off of the 3 point after about 4" taken off, though it's now on the low side of 3 rather than the high side when I started.  The meter was put into the tourpak junction on both bikes, both sat in almost the exact same physical location (bike and meter), yet I've got wildly different swr readings.  What should I do next?  I've thought about buying the FM antenna, since it's longer and restart with it.  I'm not sure the dealer is capable of doing anymore than I am. Do I need to go to the back of the radio to see if the cable has a problem- and how does going there, if I'm still using the same antenna/cable on the bike, make any difference?

arctic

[Eqcons]

The parts previously listed from "Radio Crap" will make the meter hookup simple.  

Yup, they sure would, Arcticdude!  (If we had Radio Shark here in the wilds of Scotland!)  [smiley=huepfenjump3.gif]

Jim

[RedDevil]

The parts previously listed from "Radio Crap" will make the meter hookup simple.  Just plug/play.  For those of you with knowledge, we have an 06 and an 07.  (we can't eat, but we can ride.)  The 06 needed about 2" taken off the CB antenna to get great swr readings.  The 07 can't get off of the 3 point after about 4" taken off, though it's now on the low side of 3 rather than the high side when I started.  The meter was put into the tourpak junction on both bikes, both sat in almost the exact same physical location (bike and meter), yet I've got wildly different swr readings.  What should I do next?  I've thought about buying the FM antenna, since it's longer and restart with it.  I'm not sure the dealer is capable of doing anymore than I am. Do I need to go to the back of the radio to see if the cable has a problem- and how does going there, if I'm still using the same antenna/cable on the bike, make any difference?

arctic

Arctic,
If you go to the back of the radio and get the same SWR readings, chances are it could be your coax is pinched, kinked, or bent badly...a simple check would be to connect your meter to the back of the radio, then make about an 8 ft cable (approximate length of factory coax from radio to tour pak), with the appropriate plugs on it and run it from your meter to the connector in the tour pak.  If you get better SWR readings, then you have a bad coax run on your bike.  Better still if you make the cable the same length as the factory cable, then if your coax is bad, you can replace it with the one you made, by simply adding the smaller connector to the other end and attaching that to the radio.    Don't use the factory FM antenna, if you notice, it's not the same as the factory CB antenna.  I would suggest buying aftermarket antennas, such as the J&M shorties.

cheers  [smiley=xyxthumbs.gif],
Red

[Screamin_Beagle]

Thanks for the correction fellas..........ya learn something new everyday!!!!  


_Beagle

[Screamin_Beagle]

Now you have me hooked,  does anyone know what the max output power on the FM radio's (CB's) was?  At least the legal output......I remember as a kid we would take them apart and well.....at that time we would "PEAK" the output amp to get as much power as possible.  Depending on the radio electronics we could usually get 12-14 watts (big improvement from the standard 4 watts).  Holly sh$t,  I just figured out when this whole "take a perfectly working device and make it work better" thing started for me....I gotta call my shrink....I think I just had a breakthrough!!!!


_Beagle

[arcticdude]

Isn't the mast the same between the FM and the CB antenna, only the spring/coil different.  You can loosen the allen screw and swap the actual masts themselves.  THat's what I was referring to about using the FM antenna.  That way I could start with a longer mast to then cut down.  I'm was thinking that I needed a slightly longer length to match the swr; but now realize I probably have a bad/bent/pinched cable.  Makes sense, given the rigorous QC our bikes go through.

Eqcons, if you have trouble finding the stuff local, let me know and I will mail it to you at cost.

[hogheritage04]

Red,

  Thanks for the update.  Bike looks great with those new antennas.  I guess the bottom line question for those of us who are not as technical as some of you, do these antennas work better than the stock if you were to just hook them up and not worry about the SWR issues?  Thanks again for all you work and reports.  Look forward to your response.  

[RedDevil]

Red,

  Thanks for the update.  Bike looks great with those new antennas.  I guess the bottom line question for those of us who are not as technical as some of you, do these antennas work better than the stock if you were to just hook them up and not worry about the SWR issues?  Thanks again for all you work and reports.  Look forward to your response.  

Hog,
Without actually doing an SWR check, I couldn't honestly tell you if they are better.  But if performance of my radio with the new antennas on is any indication, then, yes they are superior to the factory whips.  According to the engineer at J&M that designed them, they will out-perform the stock whips out of the bag without any tweaking.  He said that it's amazing that the factory puts those badly tuned antennas on their bikes.  I have to agree, compared to the J&M in just observable performance, they lack a lot.   Plus the shorties are much more pleasant to look at.    (I guess I should put a disclaimer in here because I like these antennas so much.   I am not associated with J&M, nor am I getting anything in return for the comments that I make here, or any sales that may arise from my comments.)
cheers [smiley=xyxthumbs.gif],
Red  

[RedDevil]

Isn't the mast the same between the FM and the CB antenna, only the spring/coil different.  You can loosen the allen screw and swap the actual masts themselves.  THat's what I was referring to about using the FM antenna.  That way I could start with a longer mast to then cut down.  I'm was thinking that I needed a slightly longer length to match the swr; but now realize I probably have a bad/bent/pinched cable.  Makes sense, given the rigorous QC our bikes go through.

Eqcons, if you have trouble finding the stuff local, let me know and I will mail it to you at cost.

Arctic,
I had a brain-fart... [smiley=confused5.gif], I was assuming you were just going to replace the whole antenna, not just the upper whip...yes, you should be able to do that with no problems...I don't know how badly those antennas are tuned, so I don't know if you need to go longer or shorter.  I hope that fixes your problem, but if you weren't getting any noticeable, either up or down, when you were trimming the antenna, it's probably not the antenna, but the coax run...it may be pinched somewhere leading up to to the fairing.  If you're not an RF tech when you're assemblying a vehicle, which I'm positive none of the CVO boys at the factory are, you're not going to pay attention to something like a kink...good luck.
cheers,  [smiley=xyxthumbs.gif]
Red

[RedDevil]

Isn't the mast the same between the FM and the CB antenna, only the spring/coil different.  You can loosen the allen screw and swap the actual masts themselves.  THat's what I was referring to about using the FM antenna.  That way I could start with a longer mast to then cut down.  I'm was thinking that I needed a slightly longer length to match the swr; but now realize I probably have a bad/bent/pinched cable.  Makes sense, given the rigorous QC our bikes go through.

Eqcons, if you have trouble finding the stuff local, let me know and I will mail it to you at cost.

Arctic,
I had a brain-fart... [smiley=confused5.gif], I was assuming you were just going to replace the whole antenna, not just the upper whip...yes, you should be able to do that with no problems...I don't know how badly those antennas are tuned, so I don't know if you need to go longer or shorter.  I hope that fixes your problem, but if you weren't getting any noticeable, either up or down, when you were trimming the antenna, it's probably not the antenna, but the coax run...it may be pinched somewhere leading up to to the fairing.  If you're not an RF tech when you're assemblying a vehicle, which I'm positive none of the CVO boys at the factory are, you're not going to pay attention to something like a kink...good luck.
cheers,  [smiley=xyxthumbs.gif]
Red

[hogheritage04]

Red,

 Thanks for the help.  I've dealt with J & M before, and I agree, they are outstanding people to deal with.  I think I'm going to go ahead and order them and see what happens.  Thanks again for all your help [smiley=xyxthumbs.gif]