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My Old K40 rides again !

whiteastro

Sr. Member
Feb 22, 2019
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Retired my Astro van because of too many issues and pulled my K40 off the roof. Was the longest antenna I could have on top because of all the trees around here. Well decided to try a Tram 3500 on my new ( used ) Ford Expedition because I had so much luck with one on my Chevy Cobalt. ( about identical length as the K40 ) Well installed the Tram 3500 4 days ago and couldn't get a good SWR no matter what I tried. Well today was going to a nice spot for installing and checking SWR on a antenna so put my old Tried & True K40 in my Expedition. When I got my work done I swapped out my Tram 3500 for my K40 in the same exact spot and climbed inside for the SWR test and with out any adjustments I got 1.1-1 on channel 1 & 40 and on channel 20 I got a Flat Liner ------. WOOO HOOO talk about a happy camper. Now it will get me excited to hook up my KL-200 P when I figure out how to tap into the power source. Makes me think maybe I received a bad Tram 3500. Any suggestions on testing it without spending a fortune?
 

NanoVNA would work. Not free, but you can find it for under $100.
Searched for it and looks like it is beyond my technical training and cost more than the Antenna it's self. Cheaper to Bail the Antenna. LOL
 
Retired my Astro van because of too many issues and pulled my K40 off the roof. Was the longest antenna I could have on top because of all the trees around here. Well decided to try a Tram 3500 on my new ( used ) Ford Expedition because I had so much luck with one on my Chevy Cobalt. ( about identical length as the K40 ) Well installed the Tram 3500 4 days ago and couldn't get a good SWR no matter what I tried. Well today was going to a nice spot for installing and checking SWR on a antenna so put my old Tried & True K40 in my Expedition. When I got my work done I swapped out my Tram 3500 for my K40 in the same exact spot and climbed inside for the SWR test and with out any adjustments I got 1.1-1 on channel 1 & 40 and on channel 20 I got a Flat Liner ------. WOOO HOOO talk about a happy camper. Now it will get me excited to hook up my KL-200 P when I figure out how to tap into the power source. Makes me think maybe I received a bad Tram 3500. Any suggestions on testing it without spending a fortune?
Just a heads up, the K40 has a ceramic matching capacitor inside the coil base and it will not like your KL-200p power, will probably burn out sending swr through the roof and possibly blowing your amp. They were designed back in the days when CB radios were just 4 Watts. Great little antenna but I would check its max power handling before you hook up your burner.
 
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Just a heads up, the K40 has a ceramic matching capacitor inside the coil base and it will not like your KL-200p power, will probably burn out sending swr through the roof and possibly blowing your amp. They were designed back in the days when CB radios were just 4 Watts. Great little antenna but I would check its max power handling before you hook up your burner.
Will Do Thanks I have made contacts with the K 40 and the KL-200P but maybe I just got Lucky
 
Many years ago I ran a Texas star 500 through a k40 antenna. When I walked out of my car I noticed smoke coming out of the k40 coil. Replaced it with a Wilson 1000. Currently I use a Sirio 5000. Nice antenna.
I hear a lot of good about that Sirio 5000
 
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I seem to remember I was fine at 200 pep watts w the k40 but when I put a 4 pill inline kaboom. I smoked the K4O.
I also replaced it with a Wilson 1000.
Still have it in the garage somewhere.
I think that K40 will be fine as long as you're easy on her.
 
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Rated for 500 PEP according to this article though as I said a 4 pill did mine in and I doubt I was doing 500 watts but it was a long time ago.
 
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I seem to remember I was fine at 200 pep watts w the k40 but when I put a 4 pill inline kaboom. I smoked the K4O.
I also replaced it with a Wilson 1000.
Still have it in the garage somewhere.
I think that K40 will be fine as long as you're easy on her.
I can't remember what the K40 is rated for. I'll have to recheck again but I do know I used the KL-200P with it and made contacts but it hasn't had heavy use so I will be ware.
 
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Thanks The KL-200 sure won't do that !
No. I think you'll be fine with that pairing.
I loved that old K40. Great ears and the twist remove was perfect for carwashes and avoiding theft.
I seem to remember I lost a little on the ears going to the Wilson.
 
I seem to remember I was fine at 200 pep watts w the k40 but when I put a 4 pill inline kaboom. I smoked the K4O.
I also replaced it with a Wilson 1000.
Still have it in the garage somewhere.
I think that K40 will be fine as long as you're easy on her.
I bought a Wilson Lil Will one time and couldn't get a good SWR with it so it soured me an Wilson so I went to Tram with good results on 3 of there mag mounts. But the 4th Tram 3500 I'm having problems with. It might be the Law of Averages is catching up with me. LOL
 
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