DYEVOUT 0 #1 August 4, 2004 10 or 12 years ago, I had a friend who would "tune" C.B. antennae to "match" the output of the radio to which they were connected. I was surprised at the performance gain this 5 minute adjustment would make. The tool he used was an SWF (standing wave frequency) meter. The meter was simply connected in line with the antenna, channel 20 selected, mike keyed open, and the antenna trim screw adjusted 'till the meter read as close to "1" as possible. Unfortunately, that friend is no longer alive - and I just installed a new C.B. in my Jeep (with a tunable antenna). I borrowed an SWF meter from a guy who has never used the thing, and it has an unlabeled dial (potentiometer), and a switch labeled "REF" on the front - which I don't remember my friend's meter having. Does anyone know how to use such a meter ? Thanks for any help. ----------------=8^)---------------------- "I think that was the wrong tennis court." Quote Share this post Link to post Share on other sites
Dumpster 0 #2 August 4, 2004 What your friend used was an SWR meter. (Standing Wave Ratio). What it does, is measure the forward power (the power going up the transmission line) in one mode and the reflected power (coming back down the line) in the other mode. That little switch switches between the two. It should have two markings one for FWD and one REF. If one is rubbed off, no biggie. When an antenna is out-of-tune (I won't get into a bunch of theory-) it doesn't radiate, and the radio waves "stand" on the transmission line. They just don't have a place to go. So this power just sits there and in a bad mismatch they can go back and fry the finals in your radio. So the better things are tuned up, more power gets into the air, and the better others can hear your signal. And you radios' finals last alot longer, too. So, hook up the SWR meter in line with the antenna, put the switch in the FWD posistion, and key your mike. The needle should give you a good swing. Without looking at the meter you have, I can't say if the meter has multiple power settings. If it's a typical consumer CB rig it probably doesn't put out more that 5 watts. Use that little knob to get a full-scale reading (or as high a reading as possible) There may be a FWD and a REF scale on the meter face. Now, unkey the mike and switch to the REF mode. Key it again - If you see a big swing, your antenna is out of tune. If it swings just a little or not at all, you should be OK. Many antennas can be easily tuned, but since we don't have a description, I can't offer any advise on that. If you can describe things in more detail, we might be able to help you there. If it's a new antenna, there should be directions on tuning it. Some antennas though aren't tunable. (as with alot of "top-loaded" antennas-) Basically you are looking for a lots of needle movement in FWD- (Lots of power going up the line to the antenna-) and little needle movement (Very little power coming back down) to make things ideal. This is measured in a ratio, and ideal is 1.5 : 1 or less. 1 to 1 is considered a perfect match. Other things to pay attention to to get better peformance - Grounding! Make sure your antenna and you radio are well grounded to the frame. At some point the antenna feedline shield (the braid on the outside of the coax-) should be grounded also. (usually at the antenna base some where-) Make sure all your connections are clean and tight and protected from the weather. CB's work with reletively low power so these little things add up!! Let me know if this helps! -Lenny Easy Does It Quote Share this post Link to post Share on other sites
ACMESkydiver 0 #3 August 4, 2004 Holy crap I worked for 3 years in military communications and I didn't know what the hell he was talking about... Gotta love Army commo...tell ya just enough to be ineffective. ~Jaye Do not believe that possibly you can escape the reward of your action. Quote Share this post Link to post Share on other sites
CrazyIvan 0 #4 August 4, 2004 QuoteHoly crap I worked for 3 years in military communications and I didn't know what the hell he was talking about... Don't tell me....Homeland Security? __________________________________________ Blue Skies and May the Force be with you. Quote Share this post Link to post Share on other sites
ACMESkydiver 0 #5 August 4, 2004 QuoteQuoteHoly crap I worked for 3 years in military communications and I didn't know what the hell he was talking about... Don't tell me....Homeland Security? Nope...I was actually active duty. All that communicative ignorance...and an M-16A1 rifle. GO ARMY!!! Bwahahahahaaaaaa....~Jaye Do not believe that possibly you can escape the reward of your action. Quote Share this post Link to post Share on other sites
CrazyIvan 0 #6 August 4, 2004 QuoteNope...I was actually active duty. All that communicative ignorance...and an M-16A1 rifle. GO ARMY!!! Bwahahahahaaaaaa.... I feel much safer now __________________________________________ Blue Skies and May the Force be with you. Quote Share this post Link to post Share on other sites
skybill 22 #7 August 4, 2004 Hi DV, Dumpster's info should get you going in the right direction. Also, make sure your connections are secure. I was having trouble with my rig (low range) so I unscrewed the connectors, cleaned them with a small wire brush and "what a difference!!" The antenna connector is out in the weather and should be monitored.SCR-2034, SCS-680 III%, Deli-out Quote Share this post Link to post Share on other sites
n2skdvn 0 #8 August 4, 2004 Quote...and an M-16A1 rifle. they let YOU have a loaded rifel!!!!!!!!!if my calculations are correct SLINKY + ESCULATOR = EVERLASTING FUN my site Quote Share this post Link to post Share on other sites
ACMESkydiver 0 #9 August 4, 2004 QuoteQuote...and an M-16A1 rifle. they let YOU have a loaded rifel!!!!!!!!! -and I was an expert marksman, too! ...still am...so back off, bi-otch!! <--Of course I don't have an M16 any more... Now my weapons are a smidge smaller, but wayyy more effective (anyone who ever fired an M16 more than once could tell you that a rock thrown pretty hard is more effective than those damn things, as they jam if so much as an eyelash floats into any of it's components...) Edited to add: Dude, where's the gun nazi?? He'd eat this up! "Oh Kennedy!!! Here boy!"~Jaye Do not believe that possibly you can escape the reward of your action. Quote Share this post Link to post Share on other sites
DYEVOUT 0 #10 August 4, 2004 QuoteLet me know if this helps! Thanks a bunch, guys I shall give 'er a go after work. ----------------=8^)---------------------- "I think that was the wrong tennis court." Quote Share this post Link to post Share on other sites
n2skdvn 0 #11 August 4, 2004 Quote<--Of course I don't have an M16 any more... Now my weapons are a smidge smaller, but wayyy more effective hey all i have is a .357 wanna go do some target pratice on some of the broken tv's i have in storage????if my calculations are correct SLINKY + ESCULATOR = EVERLASTING FUN my site Quote Share this post Link to post Share on other sites
Dumpster 0 #12 August 4, 2004 I was into the ham radio thing for a while - Until I discovered skydiving - I just finished selling my old gear for - You guessed it! - More skydiving stuff! (And a new speedometer for my motorcycle-) Easy Does It Quote Share this post Link to post Share on other sites
leroydb 0 #13 August 4, 2004 i am in the army and on top of that I am in the S1, a personnel guru... I understood him... whats up with ya'll you dont research on your own?Leroy ..I knew I was an unwanted baby when I saw my bath toys were a toaster and a radio... Quote Share this post Link to post Share on other sites
ACMESkydiver 0 #14 August 5, 2004 Quotei am in the army and on top of that I am in the S1, a personnel guru... I understood him... whats up with ya'll you dont research on your own? Like we gives a poop...I'm out!!! BTW, my hubby was in S1. Now he's just...well, to tell you the truth I really don't know what the hell he's been doing for the past 6 years...legal NCO for some reserve unit...crikey's I couldn't even tell you which one, that's how involved we are in his reserve unit. Back to the thread topic...I could figger out your reception problem if given enough time and manuals!!! It's been awhile for the tech specs, but I could still be net director in my sleep...~Jaye Do not believe that possibly you can escape the reward of your action. Quote Share this post Link to post Share on other sites
