108 whip

[jacobs132]

hi all, i just purchased a 108 whip from mfj. i dont have it yet but expect it soon, thought it might be better without having to use the spring as it is 108 inches by itself, i am putting it on a jeep wrangler , already have a ball mount above rear left tailight. i am hoping it dosent bend as much going down the road as the radio shack whip does, has anyone here used the 108 mfj whip?
,,,,,,,,,,,,,,,, jim

[cbrown]

If the whip is indeed 108" long, use it without the spring.

I've never used a MFJ whip, so I can't help you on the bending question.

[jacobs132]

i am wondering if maybe i could insert the antenna inside pvc water pipe to stiffen it or something similar, would it hurt its performance?

[cbrown]

I'd mount it first and see if there is excessive bending.

[wd8nia]

Don't know how I missed this. Having worked with PVC pipe, I'm going to speculate that the antenna will bend even more with PVC pipe over it....more wind resistance and small PVC at that length is more flexible than the antenna.

I'm familiar with the 108 and 110 inch whips. Their purpose is to increase bandwidth when using a tuner such as the Vertex FC-40; and to accommodate 160 Meters when using "screwdriver" antennas. I'm not familiar with the one Mississippi's Finest Junk offers. The ones I've used are more flexible than the particular 102" steel whip I run. You may have to do a complete RF bonding procedure on your jeep to afford you sufficient ground potential to tune the 108.

There is a stiffer version of the 102" steel whip, like the one I use, but my only source is WGS Radio Ranch in Mitchell, In. At 70 mph, there is little to no bend except for the top 18" or so of the whip....and that is relatively slight. The stiffer whip is tunable via two setscrews in the base and has very little taper in it before the top three feet.

A major contributor to bending is the spring you run. There's a heavy duty spring available that absolutely will not bend unless it's shocked hard. When you shop springs, take along two 3 inch extensions/bolts, insert one in each end of the spring, and then try to bend it. The heavy duty spring is a real bear to bend even a little. You can't really tell how stiff a spring is unless you use extensions.

Once you locate a heavy duty whip and spring, hang onto them because they're getting scarce. Here's the setup I run:

[jacobs132]

thanks for the reply, i have the jeep compltely bonded, doors, hood tailgate, body to frame, its bonded everywhere, its the radio shack 102 that is flimsy and bends easy at highway spped, i used a 6 inch spacer i made and the antenna bends in half at 65 with no spring, i am hoping the mfj 108 is stronger, it is my understanding that at 108 inches the antenna is 1/4 wave and resonant on 11 meters, i have had very low swr with 108 on ball mount on this vehicle.
,,,,,,,,,,,,,,,, jim

[wd8nia]

Sept 5, 2010 21:33:47 GMT -5 jacobs132 said:

thanks for the reply, i have the jeep compltely bonded, doors, hood tailgate, body to frame, its bonded everywhere, its the radio shack 102 that is flimsy and bends easy at highway spped, i used a 6 inch spacer i made and the antenna bends in half at 65 with no spring, i am hoping the mfj 108 is stronger, it is my understanding that at 108 inches the antenna is 1/4 wave and resonant on 11 meters, i have had very low swr with 108 on ball mount on this vehicle.
,,,,,,,,,,,,,,,, jim

YW, Jim....

After some research, I've determined I have the Procomm JBC1020 whip. Also, the Hustler IC-56 should be the same stiffness as the difference is the Procomm is tunable via twin setscrews and the Hustler model is one-piece with bonded base. Both of these are 102" 17-7 stainless construction.

Let us know how the MFJ model works out, good luck, and 73.

[Sandbagger]

Sept 5, 2010 21:33:47 GMT -5 jacobs132 said:

thanks for the reply, i have the jeep compltely bonded, doors, hood tailgate, body to frame, its bonded everywhere, its the radio shack 102 that is flimsy and bends easy at highway spped, i used a 6 inch spacer i made and the antenna bends in half at 65 with no spring, i am hoping the mfj 108 is stronger, it is my understanding that at 108 inches the antenna is 1/4 wave and resonant on 11 meters, i have had very low swr with 108 on ball mount on this vehicle.
,,,,,,,,,,,,,,,, jim

Well, you could always opt for a fiberglass 102" whip if the bending bothers you. They are far stiffer than their stainless counterparts.

[Sniper..Unit 305]

Sandbagger I was going to go the same way on my truck, that is with the old stainless whip. I too didn't want to see all that swinging from side to side and front to back. About a week ago I was looking at the Firestik 7 foot fiberglass whip, with a bit more windings at the upper end of the antenna. I guess they top loaded it to so that it would be electrically longer. I'm still undecided whether to try one or stick with my k40 in the middle of the roof. I just was looking for a change, you know, something to experiment with. Sniper

[jacobs132]

the 7 foot whip is what i have been using for a while with good results. it dosent bend as much but does a little, i am old fashioned and want to see the old 108 stainless on the back, plus you cant beat them for performance,,, jim

[Sandbagger]

Sept 7, 2010 17:09:06 GMT -5 Sniper..Unit 305 said:

Sandbagger I was going to go the same way on my truck, that is with the old stainless whip. I too didn't want to see all that swinging from side to side and front to back. About a week ago I was looking at the Firestik 7 foot fiberglass whip, with a bit more windings at the upper end of the antenna. I guess they top loaded it to so that it would be electrically longer. I'm still undecided whether to try one or stick with my k40 in the middle of the roof. I just was looking for a change, you know, something to experiment with. Sniper

Well, I have both a 7' Francis whip and a full 102" fiberglass whip. I can swap between the two of them on my truck and I can see no difference in receive signals between the two of them. I also hit fewer tree limbs with the 7'er.

[Sniper..Unit 305]

Well, it sure sounds like it is worth it to try the 7 foot fiberglass whip. I searched the internet without success in finding a 102" fiberglass whip. I am definitely going forward and will try the fiberglass whip out . Sniper

[jacobs132]

radio shack has the 102 fiberglass whip, they keep them in the back

so you will have to ask the store clerk and tell him they are with the 102 ss whips so he dosent go over to the cell phones and start looking.
jim

[Tombstone (R.I.P.)]

I have a fiberglass 102 inch whip here. I once had it mounted in the middle of the trunk lid on a Ford Escort. It matched 1 to 1, seemed to work as well as a standard steel whip but much less waving around. I didn't use the spring. It looked pretty weird though. I had to do a lot of grounding.

Tombstone

[cbrown]

Some Radio Shacks will even cut you a deal on them to get them out of their inventory. I bought 5 at one time like that.

[Sniper..Unit 305]

I didn't know that Radio Shack carried them! I have 2 Radio Shacks close to me and will try to see if one of them has the whip. I looked in their catalog but didn't see them listed. I will check out my local Radio Shacks this week. Thanks for the information jacobs132, and cbrown. I appreciate it for sure. Sniper

[cbrown]

Just make sure you get someone who knows how to look. At my Radio Shack I actually had to get the manager and show him in the back where the antennas were. I didn't think it would be hard to miss, but two sales people couldn't find them.

[wd8nia]

For reference....here's a comparison of my Francis Amazer (back in the day, "real" Amazer) 96" glass whip and Procom 102" steel whip. Take note of the second pic showing static flex.





The steel whip begins to differ in flex in the top 2 foot portion; however, on the vehicle in motion they demonstrate about the same total flex at speed because of wind resistance in the larger diameter glass whip.

The aspect that contributes to flex more than anything else respective to these particular antennas is the spring used. The most common spring found in shops today is the one shown on the Francis which I used for off roading (to lessen risk of shattering the whip). Below is a pic of the spring I use on the steel whip which exhibits absolutely no flex unless the whip strikes an object.



Now, the performance difference between the Francis and Procomm....the steel whip has the edge but that's not to imply that the Francis is not a great antenna in its own right. Compared to the steel whip, there's an RX signal loss of approximately 1 S-Unit but no appreciable difference in TX performance. For all practical purposes and intent, I consider the difference to be negligible because I have no problems communicating with stations spread out over a 5-county area with either antenna....during night time operations. During the daytime is when that 1 RX S-Unit makes a difference....more noise, more signal capture and the steel whip wins, hands down.

I stopped buying antennas when I picked up a Monkey Made while visiting friends down in Daytona Beach, FL some years back....the MM went in my scrap pile. My personal antenna arsenal picked up over the past 30+ years and I have absolutely no interest in investigating anything new. What I have perform well enough and suit my every need where versatility is concerned. Although I have a number of other mobile antennas collected up over that period, I generally only dip into the pile for kicks....here's my short list of favorites in order of performance:

102" steel whip
96" Francis Amazer
Wilson 1000
Hustler HQ-27
Performance differences between the W1000 and Hustler are virtually imperceptible.

I have recently dipped into my stash and am running a "mystery" antenna picked up some 20 years ago....just for the heck of it. It falls just shy of performing up to par with the Wilson or Hustler, but it's not a bad antenna nevertheless.



Hope this helps and 73

[jacobs132]

well i received the mfj 108 whip last nite, it is heavier at the bottom , about the same diamater at the last 2 feet, it comes as a whip and in a seperate package is the ferule to slip it into.
i laid it down on the sidewalk and put it in the ferrule all the way till it bottomed out, measured it. 108 exactly.
screwed it on the ball mount and ran with it today back and forth to work.
got good reports, when i got home tonight i hooked up the swr meter. 1.1, i am happy with this antenna.
no matter what with this length of antenna i am going to have some bending on the highway, not near as bad as with the rat shack ss antenna,
i tied fishing line a couple of feet from the top of the antenna and hooked it up to the loop on my hood. jeep wrangler.
its nice looking , cleaner with out the spring
i would recommend this antenna. its good with a little fire in the wire to.

[jacobs132]

thanks for the info wd8nia and everyone else who contributed to this thread, i really enjoy grumpy's for all the knowledge and good people here, jim
handle: jimbo point pleasant , new jersey

[wd8nia]

Fine business on your results with the MFJ 108, but it piques my curiosity further.

If you've found it necessary to tie it without a spring, it leads me to believe it's not a really stiff whip; or, you're a bit OC about it and don't like it bending at all....lol. Mine bends less than 6 inches out of vertical 2 feet from its tip and less than a foot out of vertical in its full length at highway speeds....with a spring.

Again....a tip to all where springs are concerned. Do not buy one that you can bend....period....with your bare hands.

Congratulations on the 1.1:1 match. Having to guess, I've probably done well over a hundred steel whip installs and typical results were in the 1.2-1.5:1 range without any (or much) difficulty. I can now laugh about some that were a real bear that had me cussing and throwing stuff for an hour or so. The "You want it where?" installs are the memories I most cherish now, but hated back in the day. Those required "cheats" to satisfactorily accomplish.

The steel whip is a unique critter among antennas. Mechanically, they're a sweet, slick installation after you get a few under your belt and they used to pay my rent. Electrically, they're an entirely different dealio respective to the vehicle, location of the installation, and the electrical properties involved in each aspect. You can install a 102" steel whip vertically anywhere on any vehicle, but there are instances where you'll walk away from the experience muttering, "I almost didn't do it."

Here's my honest, experienced opinion regarding the performance of the 102" steel whip compared to other antennas. You hard-mount one at the highest, center point of the metallic mass of a vehicle and no other antenna on the market will outperform it, regardless of manufacturers' or anyone else's claims. To equal its performance, and maybe marginally outperform it, another antenna will have to be mounted at that point and the whip mounted elsewhere on the vehicle; and, then most often only outperform it respective to off-directionality of the whip. Even then, I don't consider directionality to be of any consequence. I don't key the mic at stations I don't have a clear copy on; if I really need to talk to someone I don't have clear copy on, I can point my vehicle at them.

To all those expressing appreciation for our help, no....thank YOU! Your questions give us old farts an opportunity to revisit the past when it all meant more to us than it does to most people now. It's something that grows more rare as time goes by....something that can't be bought.

Thanks and 73 to all.

[jacobs132]

i have had the mfj 108 whip antenna for a couple of weeks now on the back of my wrangler, i do like it, i guess i am a little ocd about the bending, last week end i cut up a old marine base antenna and removed the inside wire antenna, cut a 3 foot piece, slid it over the whip down over the bottom ferrule and attached a rubber cap off the marine antenna to seal out water, i sliced the bottom of the fiberglass pole so it would slide tightly over the bottom of the whip then hose clamped it.
it bends now just enough when hitting limbs, but stays pretty straight at 70 miles an hour down the highway, looks good to.
it dosent bend near as much as the radio shack 102 whip with out doing anything and probably everyone one who got one would be happy with it, jim jimbo new jersey

[wd8nia]

Sept 21, 2010 18:26:21 GMT -5 jacobs132 said:

i have had the mfj 108 whip antenna for a couple of weeks now on the back of my wrangler, i do like it, i guess i am a little ocd about the bending, last week end i cut up a old marine base antenna and removed the inside wire antenna, cut a 3 foot piece, slid it over the whip down over the bottom ferrule and attached a rubber cap off the marine antenna to seal out water, i sliced the bottom of the fiberglass pole so it would slide tightly over the bottom of the whip then hose clamped it.
it bends now just enough when hitting limbs, but stays pretty straight at 70 miles an hour down the highway, looks good to.
it dosent bend near as much as the radio shack 102 whip with out doing anything and probably everyone one who got one would be happy with it, jim jimbo new jersey

Glad it's working for you but if it was excessively bending in the first 3 feet above the ferrule, I'm having difficulty envisioning it not still exhibiting what I would consider to be a lot of flex. If I were to sleeve the bottom 3 feet of mine it wouldn't have any effect on its bend whatsoever. I'm happy to take your word for it though....enjoy it because the steel whip is the anvil of mobile antennas and the only one I recommend to those who can accommodate its application.

I'm in the process of reevaluating my own antenna "arsenal." I've removed the wound, shorty glass whip seen in the earlier pic in this thread. It's performance has been adequate for local, 10-12 mile communication but unacceptable where any more distance is concerned and really hampered by directionality.

I've switched out to the Hustler HQ-27 and I've got my 20+ mile radius communications back, but there's reportedly about a 2 S-Units loss in RX compared to the 102 steelie; reports are that TX is good. I will continue to recommend this or the W1000 antennas as substitutes for the 102" steel whip when its height is unacceptable. Note that the HQ-27 is a 55" antenna. Next....the Francis Amazer.