Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

102" Whip for semi when parked?

codeman

codeman

Recovering Crackerhead
Jul 10, 2011
811
1,481
153
Currently I have a 4' K40 fiberglass antenna on my flat top freightliner, I run an older Connex 3300HP that i have had for about 12 years. It has been a great radio, taking all the abuse I could give it. Now the K40 works great, I talk to some base stations about 15-17 miles and mobile units about 5 miles or better depending on all conditions. My question is while I am parked for the evening would I get better results by running a 102" whip in place of my K40?
I like to talk skip,but I find it difficult to make contacts as I am running only about 35-40 watts from the radio. I can hear plenty of stations out there but it hard for me to get a response. Secondly I am looking at buying a sideband radio in hopes of making easier contacts, would the 102 be a good choice for that? Thanks in advance
 

There will be some improvement but maybe not a night a day difference locally but I do think you would see a difference when skip conditions favor your 20.

n0nza offered a good option but even in ssb mode with no more power than your'e using now you probably will not make many more contact, now if you add a couple hundred watts that probability improves greatly.

RCI-2970 will get you heard more locally and in skip conditions or by adding a good 200 hundred watt biased amp to your present radio.
 
If your parking in a truck stop parking lot how are you able to Rx skip with all the idiots talking over modulated on 19 with power just to talk from one truck to another parked 10 trucks from each other? Just my experience asking here. But anyway The 102 would give you a little better Rx/Tx due to length but nothing drastic. I would look for a amp and park away from the truck stops. Seeing how your a driver if your ever on 57 in Monee Illinois at the TA truck stop check out Real World Electronics located inside there. They have been there for years and do great work and give advice on radios at no charge. They will work on any radio and amp but they don't sell amps so it's not worth asking, They won't even let someone buy a amp from another person in their shop! Try me if your ever in the area Bamm Bamm on 27.385 LSB 6pm-11pm my time.
 
You'd switching out antennas back and forth. Get a 12" Predator 10K and you'll be good. As for SSB, the mentioned radios should big good candidates.
 
Thanks for the help. I am already considering getting the 257hp radio, and I am looking at the RCI2950 and 2570 as well. I am leaning toward the 257 due to it's smaller size and smaller price. Plus, I will run the unit in my pickup from time to time so the Magnums smaller size would come in handy.

As far as talking at the truckstops I drive mostly Texas and the surrounding states and I can usually find places to park where it is usually fairly quiet. I avoid those big truckstops.

I have thought about going with a 10K antenna or one like it, but I am concerned about thieves finding themselves a good antenna. But I still may give it a try, as just about everyone seems to like them.
 
Anything you replace that K40 with will perform better. Back in the day, the K40 was OK, but there are so many other choices today. It puts the K40 at the bottom of the barrel. Even if you did a simple fiberglass stick swap of your K40 with a Wilson on a Franse (spelling?), you'd be better off.
 
you could try a 102 . you,ll need either a 6 inch riser or a 6inch spring
to get swr correct. locally i woukld help a little.talking skip is just luck of
the air waves imho somedays all ya need is a coat hanger other days seems like ya need
a big beam and a big amp, its just conditions spending hundreds of dollars anent
gonna guareente your gonna be able to talk talk skip any better.and yes i would
definately get a different dive around antenna a 10k sw version would be best for a semi.
 
You know I heard and read bad reviews about the K40 antenna, but I needed an antenna and the truck stop had them for $18,so I took a chance, now I must say it is well worth the money I spent. The first day I installed the K40 I was picking up all kinds of skip and was able to make some dx contacts plus good contacts locally.

I used to run a Van Ornt Powerstick "quad rod" on a flat top day cab pulling a bulk tanker, now that setup would really get out. I used to run far south Texas back to San Antonio and was able to talk skip mostly to the south and northeast,but when conditions were right I could make the trip to Cali., Oregon, and Washington. And locally I could get out very well. Nowadays I run in an '06 Freightliner pulling a flatbed and just can't ever seem to match the performance I had with that day cab. It could simply be that conditions are just different today then they were a few years ago. Or maybe more interference from the truck itself.
 
Why don't you just run a 102" whip always? You may have to alter your antenna placement to avoid being over 14' tall, but they cannot be beat in terms of performance.

A 1/4 wavelength of 11m (CB) is approximately 108 inches overall.

The 4' firestik is approximately 48 inches in overall length, less then half of a quarter wavelength. Since it isn't a quarter wavelength, the antenna is coil-loaded. This means, a lossy coil is added to the antenna.

Average coil loss for CB antennas can be anywhere from -8 dBd (200w in, 30w radiated) to -1 dBd (200w in, 158w radiated).

A 102 inch whip represents a 0 dBd gain, meaning, it's equal to a dipole antenna. 200 watts in is 200 watts out, assuming you have a suitable ground plane. They too can vary plus or minus 1 dBd or so.

This only accounts for transmit obviously.

It should be obvious that a longer piece of metal is going to be a better conductor of energy, thus be able to pull weak signals out of the mud. You'll actually find yourself turning back the RF Gain for once, due the amount of signals you'll be picking up on Ch19, even on days with almost no propagation.

I like the RCI-2950 and the 2970.

The 2950 is nice, because you can run a separate amplifier. It's easier to fix an amplifier separately, rather than fiddling with a whole radio, plus it removes a major heat source from your radio. Not only that, but you can drive whatever size amplifier you want with it. 100w, 200w, 400w? Take your pick.

2970 is convenient as well, because it's an all-in-one package. No amplifier required, install it and forget about it. Just make sure the fins can radiate heat, or you're going to roast some circuitry.
 
Office888, I thought about doing that--- running the 102" all the time. I am thinking of putting my mount on the lower mirror bracket and maybe put a rubber hose over the bottom two feet of the whip to keep it from getting any interference from my mirror and upper bracket. That setup should leave me about 6 feet in the air and maybe a little over 14ft 3 in. high. So I don't know. If nothing else I can give it a try and see what happens or look for another place to possibly mount the 102" whip.
 
codeman said:
Office888, I thought about doing that--- running the 102" all the time. I am thinking of putting my mount on the lower mirror bracket and maybe put a rubber hose over the bottom two feet of the whip to keep it from getting any interference from my mirror and upper bracket. That setup should leave me about 6 feet in the air and maybe a little over 14ft 3 in. high. So I don't know. If nothing else I can give it a try and see what happens or look for another place to possibly mount the 102" whip.
Click to expand...

I don't know semis too well, but I know a lot of them are fiberglass now?

There was a HAM trucker I saw that uses a 102" whip, mounted in the center directly behind the cab. Fiberglass cab on the truck anyways, and the metal on the front of the trailer itself acts as a reflector. Interesting setup, but I can't comment on how it performed.

Bottom line though, when it comes to antennas, bigger is USUALLY better.
 
well i did pt work at my friends shop and semis are a different animal
and the older ones are better for antennas. for mounting a antenna
you wanna use the upper mirrior and out away from the cab as far as possible.
now with the 102 u maynot be able to use the upper mirrior mount.the k40
is a decent antenna for your money. but there is better.the day you got dx was just
conditions.i also agree the 2970 would be great for a all in one package .but
only if your planning on using ssb.alot of cash to just talk on 19.
 

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom
      Back