MH Antenna Problems

[w7wv]

Hi, new here and glad to see this forum.
I used to operate out of my truck HF with a screwdriver and that was fine when I pulled a 5th wheel.
Going full time with a 38G Winnie Adventurer n the near future and have to put HF in. Rig choice has not been made yet but not critical as I have the room. I have had a couple of 706 series and thought I might try an FT-857D, maybe even something bigger as I do have the room.
The antenna is my worry. I dealt with a fiberglass boat before and it was a problem.
I was considering a screwdriver or a tuner like the AH-4 and a whip. I will not operate other than while parked. I even thought I could just put the screwdriver directly into the receiver hitch while parked but I would think I have to have some height and/or distance away from the RV
What are you using and what problems did you encounter and how did you conquer them?
I got some ideas from Alan's site, K0BG (K0BG.com) but although he has lots of experience he has never owned an RV. Most of his site is related to cars and trucks. He does have a RV section with some ideas however.

[N7OQ]

Well Ken I have a AH-4 and have used it while camping and it works well I still use the AH-4 with my 706 while mobile I load a 102" whip and I have been very happy with it can tune 40 to 6 meters and parts of 80 even though that is a stretch for such a small antenna, but have talked on 80 with fair results. It works best on 40 and 20 because the other bands are just dead until we get some sun spots.

While camping I was string up wire antennas between trees and sometimes it is a pain to find 2 trees in the right spot and distance apart so I decite to buy a portable antenna. I bought a Buddipole, really well made but had problems with it when I first tried to use it. I was getting to much RF feed back and it was causing me to get weird SWR's and I was not getting the antenna tuned correctly. I bought a MFJ-269 antenna analyzer and discovered the feed back so I took half the coax and made a tight 6" loop and have not had a problem sense.They sell a balun for the antenna that will get rid of the feedback and some radios don't have a problem with it at all. I have worked a lot of stations sense and get good reports for portable operations.

There are a few cons with the Buddipole, one you have to move coil taps and adjust telescoping whips to change bands, two if it is raining the coils detune but a lot of Hams have installed various covers for the coils.

One of the things I have done is buy the longer whips for it and it gives you more band width I can use the whole band on 20 and up and it covers 160 khz's on 40 meters, and that is good for a shortened dipole. Another thing I plan to buy is a tripod to mount it so I can put anywhere in the campsite and get it away from the trailer. My trailer is fiberglass and RF will get into the computer interface and the antenna picks up all the noise that the trailer power converter puts out. By moving the antenna 20 feet away all those problems disappear. I should have bought the Buddipole deluxe sense it came with the tripod and rotating arm kit I will now spend more to get all that.

My friend W6KJ had a MH and he used Hamstick dipoles and he swears by them. One of the things I want to try is to put up the Buddipole without the coils using the long whips fully extended and use the AH-4 to tune it, then I don't have to worry about the coils getting wet and I don't have to move coil taps and whip adjustments. I need to find someone who has time to experiment and try the Buddipole with coils and then try it with the AH-4 and see if there is a difference in signal strength. I suggested this on the Buddipole forum and they balked at it, said it was defeating the purpose of the antenna others think it would just not work very well. Anyway it is on my list of things to do.

Sorry for the long winded post but hope some of it might be of some help.

[wa8yxm]

The Screwdriver seems to be very popular among the RV crowd.. Check out your hitch frame area (receiver area) you may have a spot where you can bolt on a plate to mount the antenna on and not have to pull it off every time you tow your car.

Another option is a short (Say 10 foot) mast you can mount the antenna on top of and mount the mast to either a hitch adapter or the above mentioned bracket, then when you go mobile you remove the mast, Make that mast eight foot and you can store it in a pass through bay

[w7wv]

TNX for the responses so far.
I like to band hop and rag chew so I would rather have an antenna I can tune from inside.
I had a buddipole at one time. Neat for portable ops but not for me.
I had thought about the mast from the hitch area (or elsewhere) to get a screwdriver or other types into the air and that may provide the mount for me just fine.
With a screwdriver I would rather be able to see it for reference marks for quicker tuning as I have had a couple of them. I could mount it up front so I could see it I guess.
I had an OutBacker at one time which worked nice but again you had to get out to change the plugs.
Someone in another forum some time ago said they used a push up fiberglass mounted pole to snake a wire up and then tuned it. I am not sure where they got the lightweight pole but it sounded good too.

[N7OQ]

TNX for the responses so far.
I like to band hop and rag chew so I would rather have an antenna I can tune from inside.
I had a buddipole at one time. Neat for portable ops but not for me.
I had thought about the mast from the hitch area (or elsewhere) to get a screwdriver or other types into the air and that may provide the mount for me just fine.
With a screwdriver I would rather be able to see it for reference marks for quicker tuning as I have had a couple of them. I could mount it up front so I could see it I guess.
I had an OutBacker at one time which worked nice but again you had to get out to change the plugs.
Someone in another forum some time ago said they used a push up fiberglass mounted pole to snake a wire up and then tuned it. I am not sure where they got the lightweight pole but it sounded good too.

I too like to band hop and this is the one thing that I don't like about the Buddipole. I might get it out this weekend and see how well it will work with the AH-4 tuner using the long whips and no coils. With the long whips you can use 15 meters and above without the coils so I'm thinking that 20 and 40 should be OK with the AH-4 but won't know until I try. The one think I know about the AH-4 you have to have a good ground or counter post or you will get a lot of RF feed back. Keep us posted on what works for you Ken.

[w6pea]

TNX for the responses so far.
I like to band hop and rag chew so I would rather have an antenna I can tune from inside.
I had a buddipole at one time. Neat for portable ops but not for me.
I had thought about the mast from the hitch area (or elsewhere) to get a screwdriver or other types into the air and that may provide the mount for me just fine.
With a screwdriver I would rather be able to see it for reference marks for quicker tuning as I have had a couple of them. I could mount it up front so I could see it I guess.
I had an OutBacker at one time which worked nice but again you had to get out to change the plugs.
Someone in another forum some time ago said they used a push up fiberglass mounted pole to snake a wire up and then tuned it. I am not sure where they got the lightweight pole but it sounded good too.
Check the High Sierra antennas.
On my p/u I use a IC706 with an Ah-4 tuner and s/s 102" whip. I have also used a francis amazzer whip but kind of like the s/s 102" whip better.:think:
I have a H/S Sidekick. I put it on a tripod on my balcony and can use it with the tripod when we are set up in a campground. It works great with the 3ft. whip it came with, even works better with the 6ft. whip you can get from h/s. But it really works great with a 102" s/s whip. Will work even better with the capacitance cap.

73
Pat

[w7wv]

OK, things just changed. I forgot that if I am lucky enough to park the RV under a tree that 23' whip I was looking at could be a problem.
I have an FT 897D coming with an AH-4 tuner that I will have to use a Better RF Tune control to use.
I am going to start out with a standard 102" whip.
At least this way I can fold it over for trees and I have added wire to a whip before to get a longer antenna to throw into the trees.
Should work just fine and make a nice mobile station for the MH.

[K3NOQ/Mobile]

I operate 100% Winnebago Mobile! Mounted a little screwdriver up on top of rear ladder, fed with RG8X. Rig is a IC7000 with the Turbo-tuner. SWR was a problem until I checked the situation with a MFJ-259 analyzer. Got everything to work better with better grounding and counter poise wires from the antenna mount. Roof of winnebagos are fiberglass. Ran one counterpoise wire into the left side awning groove. You might check your coach for a aluminum rail running up the side which serves as a lentil for the slide area. I also have the AH-4 and tried it with a 27' horizontal wire on the roof with poor radiation results.. Hope this helps, I'm still experimenting! // John

[Richard Stouffer]

I'm still struggling on the optimum set up and ain't there yet. Best so far is a wire up a 32 foot fiberglass mast mounted to the ladder. I run the AH-4 at the base of the mast and hook all that up to my Icom 7000. The biggest problem is with RF back into the rv that has tripped the GFI a couple of times.

The best results I seen by anyone else was a fellow from Michigan with a fiberglass fiver. He had a SteppIR on the roof with two radials. It was the 20 meter version. I visited his shack and he was DXing all over the place. The noise level was as low as I've seen on beam antenna's. I'm not ambitious enough to rig a SteppIR on the roof.

My next trip out I'll try hooking up the air coil I use here at the base station and, if that doesn't cure my problem, I'll look for a better grounds for the tuner and the radio. I'm probably getting a ground loop. I'll take a four foot cu stake I have and play with it.

Keep us posted on your experience.

[w7wv]

Yes I went from the 33' marine whip to the 102" whip when I realized I might get to park under trees and I would not be able to operate.
With my setup I can ad wire to the whip and have anything I need.

[K3NOQ/Mobile]

Hi Ken, Where/how did you mount the 102" whip on your Winnie? I have the luxury (?) of having a ah-4 to xperiment with. Am presently considering mounting the AH4 down low on the rear of the MH, then running a wire up the ladder via a piece of 1/2"pvc with standoffs, then accross the roof utilizing stand-offs (mounted sideways to the Lexan vent covers). My previous attempts with the AH-4 were probably compromised by inadequate grounding. Was also considering a longer 102" whip on the little tarheel but not sure if it will still tune the 6 meter band. Also bought some counterpoise metalic tape for use on the roof with the tarheel. Got lotsa ideas, and plenty of time ..... 73//John

[w7wv]

I mounted it just above the driver's door on the RV. Yes it's high and I will have to tie it down for travel but that's OK. It's up and out of the way and safe for roaming kids that wonder in.
The AH-4 needs to be grounded right at the tuner with the shortest lead possible. My ground lead is only some 8".
And I can tune 6 and 10-40 just fine. Ihave made ddecent contacts at some distance on 10-40 already with the radio without a problem and had good reports.
As pointed out, just add some wire to the whip for the other bands if you have to have them.

[k3mp]

I have been using a Comet UHV-6 in my truck for a while and I also have one for the 5th wheel...for those who have no idea what the antenna is...here is my description, but you can look it up...its a base loaded vertical with resonators, but a lot smaller than hustlers....the UHV6 comes with, 2, 440, 6, 10, 15 and 40 mtrs...I also purchased the 20 mtr resonator...I use this with my LDG z-100 tuner...but I have it resonant on or near the HF freqs I like to use on the road...I also have this set up on the top rack of the 5th wheel. When I get to a campsite and if I have room I will set up my Maldol HVU-8, that gives me 2 thru 80...along with the tuner its not that bad...good luck on your choice...

[K3NOQ/Mobile]

I have recently relocated my Little Tarheel screwdriver installation on my 2k Winnebago 35U Adventurer. W7WV,Ken sent me install photos of his whip mounting using an AH-4 tuner. This triggered my gray matter upstairs :think:and I disassembled my cabinet above the Drivers Door again. I found I had ample room to mount my Tarheel so that two mounting screws would hit the steel-cage frame of the coach, thus providing a great counterpoise. The interior of the cabinet allows plenty of room to conceal the coax, antenna motor control line, as well as the rf isolation choke. I also have room to add an additional counterpoise line for (possibly) better 80 meter operation. My SWR is flat now and radiation results so far have been favorable. My first qso (17mtrs) was VP6DX on the first call. I did see some TVI on the Sharp 32" HDTV I recently installed in the front, but its slight if any, on most bands. I actually expected it to be worse as TV is only about 3' from the screwdriver. Thanks to Ken for the FB Fotos of his install which inspired me to get out the drill. I can post some of my install if anyone is interested.

73' // John /5 Canyon Lake Texas, Lake Pointe RV Resort

[w7wv]

You are welcome for the photos.
Sometimes seeing what others have done starts you thinking.

[Clay L]

I have an old Hustler mobile antenna with loading coils from 80 to 2 meters. It worked great on my 1965 Mustang on 80m,40m,and 20m. I am considering using it when I get a HF rig. Has anyone had any experience with it?

[K3NOQ/Mobile]

Never had a Mustang, used to have a 62 Dodge though :D ......

[emu]

Haven't done this (no RV yet), but I read on some other RV site of someone fitting a weatherproof autotuner to the bottom of the RV's rear ladder, and a mount at the top of the ladder for using various mobile verticals while camped.

On the road, this ham just tunes the ladder and claims to get passable results on several bands.

There are a couple major variables in this approach: Some ladders are grounded to the chassis and some aren't. Whether your RV exterior is fiberglass or metal might make a big difference too. A radiating ladder could produce all kinds of RFI issues, both for people and other RV electronics, as well.

[Doug]

Hi...I have 38' Motorhome with ladder on rear that is attached to the chasis.. I use 102 whip on top of the ladder with RG 8x Coax.. I use a ICOM 7000 with a MFJ-948 tuner.. works well on 40-20-10.. real well with low noise.. the anenna is also grounded to the coach battery ground system.. good ground..works for me..and easy to detach when neccessary..
Doug

[Richard Stouffer]

OK, so the last camping trip didn't work out the way I had hoped: broke the 7000 and couldn't find the connector assembly to power the 706. But I did have great results with that piece of wire tied to the whip on my jeep hung on the mast on the RV ladder; at least until I busted the connector on the 7000.

I'm ready for the next trip though. The 7000 is fixed- Houston Amateur Radio in Spring Texas is great- and I have found the connector assembly for the 706. We are going to Hamfset and will stay at the Thousand Trails in Wilmington. They have some enormous trees to hang wires from. With the slingshot I should be able to hang wire as high as 80 feet.

Anybody else going to Dayton?

[wa8yxm]

I hung a KAT-1 (Marine Grade Kenwood Automatic Tuner) on the rear cap and feed it with a TS-2000 Works great with assorted long wires or push up poles. Lots of options.

A screwdriver could also be mounted on the rear as you suggest, while not the best antenna, it is perhaps the best MOBILE antenna. If you are worried about ground plane you may be able to extend a frame rail out just a bit using basically one bolt and a bit of custom cut angle iron, (No drilling required save on the extension rail) This would give you the frame as a counterpoise.

[k3mp]

Not sure what month QST did an article on mobile antennas, bang for the buck and the antennas that won out were not the screwdrivers, but antennas with resonators or sticks, like the hustler type or comet...hard to believe with all those screwdriver antennas out there. Surprised me...

[Richard Stouffer]

I read that article and I too was surprised by the finding of the two guys doing the research. I have a Hi Q 160 that I have had some success with and it is a very expensive unit requiring a lot of attention to detail to properly set up.

Exchanges on this site on subjects like this are the real value it offers.

[wa8yxm]

The QST article was no surprise to me. The screwdriver is a base loaded antenna. That makes it so popular (And for good reason) is that you can remote tune it, in fact there are many companies that make automatic tuners for it some of which interface with your radio so that you can do seamless band switching. Just change bands on the radio, push the auto-tune button and... Whirr,Whirr. tuned.

However it is a published fact (Most any antenna book) that base loaded antennas are not as good as center or top loaded antennas

The ones that outperformed the screwdrivers were all center or top loaded.

Now, a fully automatic, trap tuned, all band center or top loaded antenna. for mobile use

I don't know of one

[w6pea]

I am using my side kick on my base station IC-706MKIIG. I also use it in my RV. I works great.
I have the same radio in my P/U, but I use the AH-4 tuner. I like the side kick set up.
In mho it really depends on conditions of the bands as to which antenna set up works better.
The reason I say that is I talked to a man in SD. I'm in CA. When I was in my P/U. Got good reports from him. I talked to him at 1200hrs. PDT, I also talked to him on my base station. Got not as good reports. I talked to him at 1245hrs. PDT, the same day.

I talked to this same station yesterday, at the same basic time 1300hrs. PDT and could hardly pull him out . He claims that he is using the same High Sierra Antenna I use. except his is mounted on a pipe 12ft. above the ground. My side kick is mounted on the tripod from High Sierra and sits on a wooden balcony

[w7wv]

Just my opinion.
A well made screwdriver works very well.
The problem comes in when people try to mount them in manners contrary to the instructions that came with them.
I have seen lots of this done.
I didn't want a screwdriver on the MH. Too expensive and they are not maintenance free by all means.
My 102" whip is mostly a non maintenance item and that's good as the base is up at almost 11'. Of course I tie it down for travel.
The only downside is having to add more wire for more bands. That's OK as I like 15 and 17 for the most part anyway.

[lapipara]

I have been using a Comet UHV-6 in my truck for a while and I also have one for the 5th wheel...for those who have no idea what the antenna is...here is my description, but you can look it up...its a base loaded vertical with resonators, but a lot smaller than hustlers....the UHV6 comes with, 2, 440, 6, 10, 15 and 40 mtrs...I also purchased the 20 mtr resonator...I use this with my LDG z-100 tuner...but I have it resonant on or near the HF freqs I like to use on the road...I also have this set up on the top rack of the 5th wheel. When I get to a campsite and if I have room I will set up my Maldol HVU-8, that gives me 2 thru 80...along with the tuner its not that bad...good luck on your choice...
I have a uhv 6 antenna. I intend to mount this to a pole attached to the frame of my firberglass 5th whee. Will that give me enough of a ground plane. Secondly how did you tune it. I put it all together adn attempted to tune it with a mfj meter. My swr readings were all over the place. Any suggestions would be appreciated.

[Richard Stouffer]

I think you will need to use the frame for you counterpoise. Fiberglass won't do a thing for you in that regards.

[w7wv]

I suspect that he is really not hooked up to a "frame" or ground reference.
Many times ladders, gutters and such on RVs are not ground electrically.
You need to check this out and make sure.
And many older RVs that I have had have wooden frames holding the fiberglass up so there is no ground there either.
Use a meter and find out if what you are hooked to to really the frame or negative side of the battery.
You just might be surprised.
Boats are even worse to deal with, been there and done that.

[k3mp]

I have the antenna mount grounded to the rear bumper of the 5'er...as far as tuning...I tuned it on my truck before I put it on the 5th wheel...I also use a LDG Z100 tuner to assist in getting the SWR even lower...have no problems with it...sometimes I also put out my MALDOL HVU-8....another nice portable antenna for camping...but somewhat cumbersome...