10k.Boy was i wrong!

[jessejamesdallas]

Ya that was the thing that botherd me was that there was different types and the guy that sold them didn't know any better about the aplication.
10K223-just wondering what type would you sugest for centre roof top mount grounded at the base (no magmount here) on my little puddle jumpin VW.
I've tried your experiment with the my friend 30min away across the open country in an open area on a hill and the only difference was my match. The 102 was almost flat.
The one I got right now is the one with the short base element and 2 coils and I cut the top down till I got to a 1.5 and can't get it any lower no mater where I go around the band.
The reason I got the short base element because it's goin on my Suburban when I get an extra radio.
So the next one I buy will be the right one I hope.
We just wana get shorter because with the 102 bolted on the roof goin down the back road doin 60-70 cleaning brush over head can be a little anoying some times.
Mind ya 10K or 102 people still have that WTF look on their face when I roll by, nuk nuk.

If you go with at least a 17'' shaft on your puddle jumpin VW, you'll see a "BIG" difference in your swr.

On your Suburban, with the 10K placed at the very back, if you run the 22'' shaft Dual Coil 10K, your swr should be @ 1.0 to 1.1 across most of the 40 channels.

With the 27''shaft Dual Coil on the back of a Suburban, Channel 40 will be 1.1, and channel 1 will be 1.1....The rest will all be lower. (this is providing you have a perment mount, and a good meter/ or use a mfj analizer...)

 

[CDX197]

from what i have heard is 10K antenna's are the way to go. Havent gotten one yet but plan to. Hell i dont even have a radio for the mobile anymore :? . But from what i have heard its a 10K World!

 

[LoneWolf TN]

s

Kale, I have three different shaft length 10k's, 17", 27", and 36". I also have two short coils and three long coils for the 10k's. I have mounted the 10k's in different length and coil configurations just about everywhere and can't get below a 1.3 swr and fairly high reflect. Maybe they don't like my Ford pickemup. I don't know. I also mounted the 102" whip in many different locations with high swr and high reflect, until I mounted it just behind the cab on the driver side bed rail - 1.1 with almost no reflect. I'm not saying your antennas aren't great, they are. They just aint working on my pickup truck...

Just my experience, LoneWolf TN

 

[Marconi]

LoneWolf, don't let me through you off your pace here, but I thought there was some relationship between SWR and reflect as you note in this thread. Yet you speak of the two as one going one way and the other going the other.

How do you measure reflect?

 

[LoneWolf TN]

s

Hello Marconi, it seems when I have a slightly higher swr or a much higher swr the reflect usually is higher also. When I get an almost flat swr reading I usually have a very low reflect.
When I check the reflect I use a buddies MFJ.

LoneWolf TN

 

[Marconi]

Well that is pretty much what I understood also. I guess I just misread you words.

 

[jessejamesdallas]

Re: s

Kale, I have three different shaft length 10k's, 17", 27", and 36". I also have two short coils and three long coils for the 10k's. I have mounted the 10k's in different length and coil configurations just about everywhere and can't get below a 1.3 swr and fairly high reflect. Maybe they don't like my Ford pickemup. I don't know. I also mounted the 102" whip in many different locations with high swr and high reflect, until I mounted it just behind the cab on the driver side bed rail - 1.1 with almost no reflect. I'm not saying your antennas aren't great, they are. They just aint working on my pickup truck...

Just my experience, LoneWolf TN

Just wondering...you didnt realy say, but did you try the 10K on the roof?

If you did, and got high swr reading, that may be because alot of Ford Trucks, the roof has a poor ground. And may be nessesary to run a separate ground strap, off the antenna mount itself, to the frame of the truck. Bed's are the same way, sometimes when mounting on the bed of a truck, you need to ground the bed, generaly at all four corners for best results....

 

[10k223]

Re: s

Kale, I have three different shaft length 10k's, 17", 27", and 36". I also have two short coils and three long coils for the 10k's. I have mounted the 10k's in different length and coil configurations just about everywhere and can't get below a 1.3 swr and fairly high reflect. Maybe they don't like my Ford pickemup. I don't know. I also mounted the 102" whip in many different locations with high swr and high reflect, until I mounted it just behind the cab on the driver side bed rail - 1.1 with almost no reflect. I'm not saying your antennas aren't great, they are. They just aint working on my pickup truck...

Just my experience, LoneWolf TN

LoneWolf, The 17" shaft and the 22" shaft should get lower than the 1.3 reading. There is nothing wrong with 1.3 at all. You guys are spoiled to flat swr readings when it doesn't have to be that low to perform well. There is now noticable difference in performance from 1.5 on down to 1.0. Run the 10K for a week at 1.3 and then put the 102 on at 1.1 and see which one you like the best. Kale

 

[Mr Clean]

I have been told that you can see more of a difference with the 10K when you have alot of ground like a Burb supplies. Not as much with trucks and such. Anyone found this to be true. I am asking because I don't know. Not trying to start anything. Thanks for any imput.

 

[LoneWolf TN]

f

I've run 10k's for several years now along with Coilys. I'm not bitching about the 1.3 swr - that suits me just fine. It's the high reflect I seem to get with the 10k on the pickup that worries me while running the DaveMade. For some reason I just can't get the reflect down with any of the top notch coil antennas. The 102" whip mounted on the side rail behind the cab is the only antenna and location I have been able to run with very low reflect. Jesse James, I have everything grounded on the p/u.
I think my next move is to purchase a quad magnet mount and give it a try on the roof. Heck, I even had a pipe mounted directly behind the cab reaching above the roof of the cab. The antenna mount was about 3" above the cab. That left nothing (I thought) to cause reflect, but I still had a reflect problem. Who knows...

LoneWolf TN

 

[kd5drx]

Re: f

I've run 10k's for several years now along with Coilys. I'm not bitching about the 1.3 swr - that suits me just fine. It's the high reflect I seem to get with the 10k on the pickup that worries me while running the DaveMade. For some reason I just can't get the reflect down with any of the top notch coil antennas. The 102" whip mounted on the side rail behind the cab is the only antenna and location I have been able to run with very low reflect. Jesse James, I have everything grounded on the p/u.
I think my next move is to purchase a quad magnet mount and give it a try on the roof. Heck, I even had a pipe mounted directly behind the cab reaching above the roof of the cab. The antenna mount was about 3" above the cab. That left nothing (I thought) to cause reflect, but I still had a reflect problem. Who knows...

LoneWolf TN

I may be mistaken as i've only been fooling around with radiosw since the 60's but isn't SWR actualy the relation ship between forward and reflective power. if you put a bird wat meter in line you have fwd and reflective settings and that corosponds with a SWR on a chart provided by bird. after all SWR stand for standing wave ratio. So if you have a low swr how can you have a high refletive reading put an mfj analyzer on the antenna its self with out a mount and see if the antenna it's self is resonate at a given freq. then mount the antena and see what he reading is on the same freq once mounted it should be the same all things being equal. if there is a differance you have ground trouble or coax trouble. as far as ratio most any good radio or amp should work as long as the swr is below ay 2:1 match the lower the better of course as the ratio goes up the less power actually goes out the end of the antenna.

 

[WolfRadio.com]

The 17" shaft and the 22" shaft should get lower than the 1.3 reading. There is nothing wrong with 1.3 at all. You guys are spoiled to flat swr readings when it doesn't have to be that low to perform well. There is now noticeable difference in performance from 1.5 on down to 1.0. Run the 10K for a week at 1.3 and then put the 102 on at 1.1 and see which one you like the best. Kale

I agree 100 percent Kale. Some people have the belief that if the match is perfect, pure resistance, 0 reactance, there signal will some how be launched in some superior way from the next guy! It simply is not the case. It’s next to impossible to detect the difference from a 1.0 match to a 1.4 or 1.5 swr at the receiver. It doesn’t matter if you have 2 watts or 20,000. A 1.5 swr equals 4% reflected power, at 2 to 1 reflected is up to 11%, and at 3 to 1 = 25%. A four percent loss of power is like a couple zeros behind the decimal in dBs, practically nothing.

As people are finding out, steel does not make a good antenna. It’s just not that good of a conductor at rf. It’s not good to use for amplifier chassis either, it causes arcing in the presence of strong rf. If you ever want to see exactly where the major losses are in an all steel whip (one or two piece) dump about 10 or 20 kilos into one for about 15 to 30 seconds! Do it in the dark at night for best effect! To be safe stand at least 8-10ft. back!!

Lone Wolf. The pipe on back of the pickup like that is a classic way to mount the antenna. I used that back in the ‘70’s, and its still good today. I never had problems with it. If you already added ground straps in the correct way it should work. You may have a special case?? It can also be a false reading; most transistor amps won’t show low swr regardless of what you do with certain antennas. I have seen it rise up as high as 2 to 1 or more and was normal with some amps.

A word on the MFJ antenna analyzers - they work well for what they are, I know, I have 3 of them. I do all kinds of tricks with mine, but no two give the exact same reading. They are not a Lab Standard piece of gear, the readings are not written in stone, and they are sensitive to external rf. The best way to fine-tune the antenna is with a Bird type meter and low power slug in reverse using a barefoot radio (6-10watts), or just any good swr meter and barefoot rig.

Wolf

 

[W5LZ]

Ready for this?

Conductivity of metals makes very little difference at HF. Copper, steel, aluminum, platinum, gold, silver, no practical differences at HF. Want to use gold as an antenna, be my guest, but you're wasting your time.

SWR meters have no idea what reactance is. Can't measure it, doesn't know when it's there, so can't tell you anything about resonance.

Antenna analizers can tell you if there is reactance present. What's done about that reactance is up to the operator. Reactance present means nonresonance.

Exact readings just don't mean very much in general. If the readings are 'close', you will do as well as if they were correct to 10 decimal places.

Bird watt meters. ~Used~ to be the standard things were measured against. Now, not really any more accurate than several other brands, and readings are always dependant on what the operator knows about electronics. Still good for 'bragging rights' though.

Loading coils always introduce losses. Certainly not that much of a problem if you have to use a 'shortened ' antenna. Still means that they do not do as well as 'full sized' antennas. Does make for a viable option when 'full sized' antennas can't be used, but never the 'best' radiator.

Not the easiest things to digest, but once you get used to the taste, very healthy...
- 'Doc

 

[DTB Radio]

If someone wanted to test the 102" whip (or any otehr antenna) against the 10k in a reasonably controlled setting, they could assemble a large (18'x18') flat steel surface, and rig a mount in the very center. Support the surface a few feet above the ground to simulate height on a vehicle, run your coax under it, and do field strength tests with the various antennas you want to test. That should definitively tell you which antenna(s) have the best over-all performance. I understand that a vehicle doesn't offer a perfectly flat ground place, and that different vehicles will work better with different antennas, but that method would at least single out the better ones to work with. In theory, once you determine which antenna is best in the control setting, its just a matter of finding the best mounting location on your particular vehicle.

 

[WolfRadio.com]

SWR meters have no idea what reactance is. Can't measure it, doesn't know when it's there, so can't tell you anything about resonance.

I hear ya Doc. Are saying that if I have a reading of zero reflected power - I can still have reactance in the load at that frequency? It’s my experience that reactance causes a faster rise in swr from the resonant freq. than does a change in resistance alone. Is this wrong? Please advise.

I must disagree about the performance of different metals (skin effect) at very high power levels especially the steel. I know they make broadcast antennas out of plated steel. But I have made steel whips come to a glow with high power. It happens about 2-3ft up from the base! Aluminum does not do that, although the diameter is usually larger on the aluminum. What else would explain that?

73's Wolf