Amateur Radio (HAM) in the Motorhome

Looking for advice on installing a 2/70meter antenna on a Coachman Santara 311SB and possibly an HF antenna.
I have a Handheld 2/70 meter but would like to install my Yaesu 857D.

Thanks in Advance

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ROB357 said:

Looking for advice on installing a 2/70meter antenna on a Coachman Santara 311SB and possibly an HF antenna.
I have a Handheld 2/70 meter but would like to install my Yaesu 857D.
Thanks in Advance
reply to
 [email protected]

Click to expand...

I have a Kenwood V7A in the MH with a very short dual band antenna.  The set up works fine but I have to move it as the wife, also a Ham, doesn't want it on while she is driving.  I will put it down low on the wall behind the driver's seat and the head right beside me.  I have a long cable set for the head that should do the job for the relocation.   

At the same time I will do the runs for a HF rig that will mount behind the driver on the computer desk.  

Good luck,

Hello,

I run a 36' MH.  I have a IC 7000 bolted to the dash with an external speaker.  I really enjoy working mobile.  I had a bracket welded off the side of my hitch and up the back of the coach.  On top of the bracket I installed an ez-lift.  It's like a garage door opener and runs the antenna up and down.  The Icom has 2/70m however you can't listen to both hf and vhf/uhf at the same time.

I installed a dual band antenna on the side of my ladder.  I keep the tip of the antenna same level as my a/c so it does not hit anything.  You can use a piece of angle iron on the ladder using U bolts.  Run the iron across behind the steps and bolt around the up rights.  Leave enough iron past the ladder uprights for the antenna.  You can either drill a hole in it or use various mounts available, your choice.

I used to use a Hustler antenna with a quick disconnect.  You can find a mount at Radio shack for a truck mirror.  I only used that setup when stationery.
Many Hams use the bumper for mounts they design.  I have seen many tilt over mounts on the top of the ladder.

I send you a few sites worth looking at.

73, Russ - WB3FQI/6

This site has a wealth of information:


http://k0bg.com/

I use this,  a bit expensive but I can't climb to install antennas.

http://antennaezlifter.com/

73, Russ - Wb3FQI/6

For 70CM I have my choice of 2 antennas, One is a NGP antenna (no ground plane) on the roof, about 5/8 wave if I recall.. I bought this one, screws onto a standard UHF (PL-259 type) coupler, the coupler is a six inch feed through, the lower end is inside a wall (Was supposed to be inside a cubbord but I missed) and from there to a junction where I can switch antennas

Antenna 2 is a T-POLE  this is a "T" shaped piece of 1/2 inch PVC (1" would have been better)

If you set it up like the letter "T" the upright is a quarter wave "Stub" of TV-Twin lead (Standard 300 ohm TV wire, 450 Ladder line could be used too, impedance matters not on this wire)

The Top arms are each 1/2 wave length..  Look up a J-Pole that is the basis for this design

A standard "J" is 1/2 wave length on top of a quarter wave of matching stub.. I bent the connection 90 degrees and added a 2nd 1/2 wave to the other side of the stub.  Feed it as you would a "J"

This antenna is "loose" and can be mounted on top of a flag pole, either flat (horzontial) or Vertical.

For 2 Meters I mounted a J-Pole on the rear fiberglass cap.  I also have a 2nd "T" for the flag pole

I plan on tossing the two "T"'s on the roof (lay flat) and seeing if I can hear/work any satellites or the ISS

Page 2. Low band

I mounted a Kenwood Automatic Tuner (KAT-1, marine grade) on the rear cap. I have 100' of wire connected to the wing nut and tossed over some trees

I also have 30 feet of 1/2 inch copper mounted 5" above the roof (looks like a luggage rail but not nearly as strong) and 10ga wire from there down to the cat, about 36' total (minimum for the KAT is 25 feet) I've not yet tried it out since I mounted it last week

I also have a hustler 4BTV bolted to the bike rack.. Next to the KAT... Since I feed it with the KAT (Even though they say not to) I did away with the capacity hat on the 40 meter segment (Top segment)

I have also used 35 feet of copper pushed straight up but wont' be using that any more.  (Part of it is now bolted to the roof in fact)


Feeding all the above is a Kenwood TS-2000

My prefered mode.. Once I get a reliable computer back in the shack (Should happen around labor day) is PSK-31  20 or 40 meters

I am running two rigs in the motor home.

The first install was a Yaesu FT-857D, which I installed next to my left knee in the driving position.  It was my first HF rig, and decided to go with an uneducated guess of using Yaesu's ATAS120 with it, which I mounted on a modified mirror type mount which was screwed through the wall into the driver's Seat Belt Pillar, which ground to the entire steel subframe of the Motor home.  The Install works as it should, though the Yaesu screwdriver is a very small screwdriver, and is very much so a compromise.  All that said, it matches well, and talks OK for what it is.

After several months of use, I decided that it wasn't the best situation for operation while parked, which as full-timers we are parked for long periods.  One of our first mods to the coach was the removal of a Jlounge and install of a full size desk, which is where one of us spends most of our time.  This turned out to be the optimum spot for a "Portable Base" station.  My first attempt at this station was building up a complete FT-757GXII with auto tuner and matching PS/Speaker.  This was a "Lower dollar" way to prove that we liked the radio there, and then decided we wanted a tad more modern radio, so we acquired an FT-897D.  I wanted portability also, so I did get the batts, and decided to use it on an Astron AS35M Power Supply.  I knew I wanted a tuner and at the time the best idea seemed like the LDG AT897.  It is currently hooked to our Macbook with both a Cat cable and the SignaLink USB.  I use a Diamond SX-600 Watt/SWR meter also.

For antennas, currently I am running coax through the floor, and on the ground to the rear ladder, which I have 2 lengths of Chain Link Fence "Top Rail" bolted together (11 ft section of 1 3/8" steel tube) and then hose clamped to my rear ladder.  On top for HF I am using a Solarcon A99, which matches 20-6 well, and does work on 40.  It isn't the most efficient on 20, and well, it jsut works on 40, but it does work well as I have made a ton of PSK and SSB contacts with it, really I think it's advantage is it being 40 ft high (22 ft of mast and 18 ft of antenna).  For V/UHF I am using a dual band base antenna on a similar mast on the opposite side of the ladder, which works super well.

Negatives are take down and setup, and the inefficiency of the HF antenna.  I used what I had or could get cheap, and it works, but not optimal.  I think my next step is going to be mounting a Dual Band Mobile u/VHF antenna on the Passenger side seat belt pillar similar to how I mounted the ATAS, and the HF I am leaning toward spending the money on an SGC or similar auto matcher and either doing a marine SSB whip on a tip over mount or a Whip on a ball mount that I could attach additional wire too if I wanted.  My ideal situation would be little to no setup/tear down in making the transition from Mobile to Portable, but yet the flexibility to pull the radio quickly and take a portable antenna anywhere I want.

I haven't done this yet mostly from lack of funds, and if I were to start again this what I would have done to start with.  I would like to see a setup like this before I did it, but haven't run into anyone that has done it yet, as I do have some questions as to where to mount the auto coupler and such.

John

I have a Kenwood TM-733 and 2 CB's next to me when driving (Chan's 19 and 13 on the CB's) a hand held on 146.52 sitting in a charger base on the dog house as well.

That is the "IN-Motion" set up.. I will add additional capability (6mtrs) next time I have a spare 25 bucks.

The MAIN rig,is a Kenwood TS-2000,it's mounted in the "half bath" on my bath and a half model, 160 through 2 meters, all modes. feeds an assortment of things. for "low bands"  (160-10) It feeds a KAT-1 Auto Tuner,marine grade, that hangs on the back ofthe bus (on the rear cap) this feeds a long wire, I toss over tree lmibs.. Current wire is 43 foot but I think I'll go back to 100 next time I park.

For other bands I have a six meter quarter wave, 2 meter "J" pole, and 70cm 5/8th (I think) fed a a no-ground plane

I also have a 6 meter dipole, a 2 meter "T" pole and a 70cm "T" pole

What's a "T" pole?

Well, if you look up the "Super J" which I think was in last month's QST,  that is the basic design but with a change.

A standard"J" is a quarter wave matching section with a 1/2 wave radiator

The Super J, put a quarter wave phasing loop on top of that half wave and then stuck a 2nd half wave on top of that.

WHat the T-pole is, is the same design, only drop the quarter wave stub on the bottom, and feed the phasing harness.

These can be set up either horzontial or vertical, and themount is a flag pole,25'

John, do you have any pics of the KAT-1?

I assume the Kat-1 is very similar to an AH4 or SGC 237?  What do you do about the RF ground?  How long is the braid/wire to the ground?  Would it make more sense to mount the tuner right on the frame underneath to make the ground as short as possible?  Your thoughts on Performance?

Here's my dilemma, I mostly work 10 and 20 right now, though I would love to be able to play on 40, 75/80 and even 160 in the winter, but what I have now is cheap, and I have made some good contacts on it, but the setup is a bit tedious (a 22 ft pole with 18 ft of anything is a bit of a challenge to raise alone...) and it has the advantage of being fairly "Non Intrusive" as it is completely supported by my rig.

I do have a slingshot deal, but there are a lot of campgrounds that simply don't have big trees, or big enough sites.  So my thought was the SGC or similar feeding a 23 ft Shakespear Marine SSB antenna on a knock over mount.  That way in theory anyhow I could operate either vert. or horizontal, and setup would be a matter of clawing up on the roof and standing it up. I have two concerns, one, it is costly, and two, I need to know it will work at least as well, if not better than my current system.

Well, there are two RF-Grounds.. or rather counterpoise. (not truly a ground, Believe it or not you do not need a ground, you need a counterpoise.

The frame of the motor home

Or a very very long screwdriver driven(Pushed) into the ground and though a 10ga wire.

The KAT-1 is just an auto tuner,, One of many that are out there.. Looks identical to a Yesau and a Icom I've seen (Box with a screw on tip) This one is marine grade (Sealed against weather)

Grain-of-wheat bulbs can be purchased in hobby shops. Specifically the ones that sell mini railroad setups. They come in various voltages.

Carson, I think I missed somehting about the GOW bulbs?

John,  Yes, I know the difference between counterpoise and DC ground, and have been reading K0BG's site for a while...  I must say I have learned much from him, but has left me with more unanswered questions...

You said you mounted your KAT1 on your back cap, is it exterior?  or did you mount it inside the rear cap?

How did you bond it to the camper frame?  Braid?  Flat copper?  How close/how long of braid/wire did you use?

Do you have any problems with high voltages coming off the end of the long wire?

What about RFI problems? 

How well does it work?


After reading so much info on K0GB's site, I am thinking my original thoughts might be better served in a different location.  A couple points that he had struck a chord...  Completely obvious ones, but none the less things i haven't thought about.  One he mentions that a vehicle's body really isn't a ground plane, but rather a capacitor to ground, which explains why having the antenna directly over it is so important.  Which also explains why installs in modern RV's are so difficult.  Now my thought is to keep things close together and in proper arrangement maybe the auto coupler's best install point would be on the roof, or even just below the roof inside in a n upper cabinet?  I have a location near the rig where I could drill through the roof, and also through the cabinet to bond to a nearby steel beam, however, before drilling holes, I would like some opinions.  This would be fairly close to the rig, (4 or 5 ft) about 6 inches form a good bonding point to the frame, and just under where I could install an insulator though the roof line.  Concerns would be there would be about 6 inches to a foot of "Hot" antenna inside the RV coming from the terminal of the Auto Coupler.  On the roof I could either attach a wire, or use some type of mobile mast or somehting?

Any thoughts?

John,

Carson, I think I missed somehting about the GOW bulbs?

Click to expand...

  Am trying to figure out what you missed.  ???

  Model railroad fans use them for lighting in their trains. They are also used in ham radio equipment for backlighting the instruments. See here GOW bulbs.

  I searched heavily some time ago.. Radio Shack a no go. 

Hope this helps out.

73 carson FL

Radio Shack, used to be Radio Shack, they had a good assortment of parts and "Stuff" today they are basically Cell Phone Shack. not much of anything in the parts dept. Few connectors, Can't even get UHF (PL-259) fittings there any more

THe KAT-1 is mounted on the outside of the cap. it's marine grade so it's water tight and can be mounted in a non-weather protected place.

It's bonded to the frame with 10ga wire

And from there to ground, when I choose to plant the ground rod