Amateur (ham) Radio in a TDI

I'm a new 2009 SportWagen TDI owner (4 days so far), and a ham radio operator.
Any other hams out there with specific recommendations on installing ham gear in the car? I'm seeking advice on providing good power to equipment installed in the rear as well as installing a VHF/UHF dual-band antenna.
As a temporary measure, I've got a cig-lighter plug powering my APRS gear in the back, but would like to do better (at least tap a feed off the wiring going to the cig lighter, if not run a big fat pair of wires from the battery).
In the vehicle we traded in I had drilled a hole in the roof and had a permanent NMO mount there. Worked great, didn't have any wires going through door or hatch gaskets, and didn't have to worry about mag mounts scratching the roof. I've got the monster sun roof with retractable sunshade, so I'm not sure how much room there is between the headliner and the sheet metal in the back should I decide to punch a hole for an antenna.
David, ky7dr

David

My cars are older than yours, but I ran a big amplifier cable from the battery all the way to the trunk, routed underneath the door sills all the way to the trunk, then I installed a current distributer block to get all the power from there (you can buy all these items at any stereo store), in my Golf I have the TMD700 VHF-UHF, and in my Jetta I have the TS2000 with the RC2000 and the ALS-500 hooked up, I have never had any problems, and for antenna mounts I have the K-400 nmo mount, mounted on the door close to the rain gutter in both of my cars, they work like charm when it comes to SWR too,,, I would not recommend drilling holes on the roof since it is a new car and there are better options now at HRO or any other ham store to buy mounts that do not need drilling.

If you need any more help let me know

Robert
73
KQ6NA

Robert:
Thanks for the input.
I used to be a lot shyer about drilling antenna holes in vehicles, esp. when new.
When I finally bit the bullet and drilled for an NMO mount in the center of the roof of our previous vehicle, I was so happy with the clean looks of just the antenna there and its performance that I vowed to never wait that long to do a proper antenna install.
But if I can get a good install with one of the modern mounts to the luggage rack or lip of the rear gate, it would be easier and less of a "commitment".
Of course there are a zillion mounts out there, and hard to tell from a web page which ones are high quality and would work well with this particular vehicle. I'll see what I can find.
Thanks, 73, David, ky7dr

cq cq cq de ke4mbn ...sorry I don't have a rig in the jetta yet.

rushtone said:

Robert:
Thanks for the input.
I used to be a lot shyer about drilling antenna holes in vehicles, esp. when new.
When I finally bit the bullet and drilled for an NMO mount in the center of the roof of our previous vehicle, I was so happy with the clean looks of just the antenna there and its performance that I vowed to never wait that long to do a proper antenna install.
But if I can get a good install with one of the modern mounts to the luggage rack or lip of the rear gate, it would be easier and less of a "commitment".
Of course there are a zillion mounts out there, and hard to tell from a web page which ones are high quality and would work well with this particular vehicle. I'll see what I can find.
Thanks, 73, David, ky7dr

Click to expand...

The problem when mounting an antenna with the any luggage racks, bike racks or cargo racks, is that you lack of a good ground and you most likely will not be able to tune your antenna for best SWR, unless you run a grounding strap from the rack to the body of the car,,, but with some of the new antenna mounts now a days you are able to mount them on trunk lip or the door lip, which will give you good grounding, unless the door or trunk mount are islolated, but connecting a good grounding strap in any of these situations will always work.

rushtone said:

I've got the monster sun roof with retractable sunshade, so I'm not sure how much room there is between the headliner and the sheet metal in the back should I decide to punch a hole for an antenna.
David, ky7dr

Click to expand...

Hi David,

Congrats on your TDI purchase and Welcome to TDIclub!

I think you're going to have to pull the headliner down and operate the sunroof system thru its range of motion and see EXACTLY how much roof space "real estate" you really have. You don't want to guess at it because you only have one chance to drill the hole in the right spot.

An NMO roof mount is definitely the way to go for a clean and professional look and best antenna performance. I have an NMO roof mount on my 02 Golf for 2m/70cm and love it. I'm using the Larsen NMO 270 dual band antenna.

One thing I love about a radio installation in a TDI is that there is absolutely NO IGNITION noise to worry about like there is in a gasser! Except for a little bit of broadband noise from the car's computers in the VHF range, I've found the car is overall VERY RF-quiet. It's great for AM broadcast band DXing at night. Although I'm not into HF at all (I'm a VHF/UHF guy), I would expect the HF bands to be clean as well.

73's and good luck.

rushtone said:

As a temporary measure, I've got a cig-lighter plug powering my APRS gear in the back, but would like to do better (at least tap a feed off the wiring going to the cig lighter, if not run a big fat pair of wires from the battery).

Click to expand...

I tapped off the cig lighter circuit in back in my 02 Golf TDI and it works great with minimal noise and voltage drop, even at 50W transmitter power (~ 9A current draw).

I'm assuming your cig lighter circuit in back is the same as in earlier VWs and if so, it's a dedicated 30 Amp circuit. The wire size is 10 gauge, IIRC. The wires are beefier in size than the cig lighter socket in front. That socket in the rear is meant to power accessories and it looks like VW designed for it.

I decided to run my power connections from the socket circuit in back after finding what a royal PITA it is to get wiring thru the firewall to the battery. Another option is to connect to the bus bar at the main fuse block assembly under the dash. Be sure to fuse it properly if you go this route!

Good luck.

Hallo all Hams' where about you have mounted your VHF/UHF radios?
I mounted my Yaesu FT-1500M on the pasenger side of gear shifter console becouse it would'nt fit on the front panel of my 2003 wagon.

Yeah how about we post some pics of our installs. Now you got me temped to place a FT100 or something in the TDI hehe

There is a power take off (stud) marked 75X under the dash board on the drivers side near the relay panel. It is hot when the key is on.

The diamond K-400 mount comes in NMO, UHF, and even 3/8x24 and is a good mount.

Most dual band antennas I have seen cannot be successfully retuned, but they hardly ever need to be either... (Right from the factory they are usually under 2:1 all across both bands, which is good enough to run)

73's

Bill

I have not had any problems tuning mine with the K-400 mount, when Iinstalled the K-400 I took out that little aluminum plate that protects the door lip and screwed those little screws to the door lip, and I never had any problem tuning it I always get 1.1 in most of the 2 meter and 440 frequencies, of course I had to adjust the whip.


Parahiker I mounted my radio in the trunk, and ran the controller cable all the way to the front of the dash, my radio has a detachable face.

I have mounted radios in both a 2000 Beetle and at present a 2001 Jetta. Power was tapped off the bus and run into the trunk. The power was then connected to a distribution box and from there to a RIG Runner with Anderson poles. The HF radio is an IC-706 and the VHF/UHF radio is a Kenwood TM-V71A. HF antenna is a screwdriver from HI-Q and is mounted off the tow hook with some extra pieces. The VHF/UHF antenna is a Diamond dual band using a K400C mount. The TM-V71A allows me to do aprs (AA9VT-9) while monitoring and talking on local repeaters. APRS is done using a Tiny-Trak 3 and a GPS antenna/receiver. The TM-V71A head is mounted in front of the shifter and the IC-706 head is mounted on a goose neck that is connected to the passenger seat track. I lost a little bit of seat room on the passenger side....

73's AA9VT

Who here has a EchoLink near them? We should all dial into one and have ourselves a nice TDI radio chat.

Figured I'd chime in w/ my call as well. kj4bwu

73's

ke4mbn here

rushtone said:

I'm a new 2009 SportWagen TDI owner (4 days so far), and a ham radio operator.
Any other hams out there with specific recommendations on installing ham gear in the car? I'm seeking advice on providing good power to equipment installed in the rear as well as installing a VHF/UHF dual-band antenna.
As a temporary measure, I've got a cig-lighter plug powering my APRS gear in the back, but would like to do better (at least tap a feed off the wiring going to the cig lighter, if not run a big fat pair of wires from the battery).
In the vehicle we traded in I had drilled a hole in the roof and had a permanent NMO mount there. Worked great, didn't have any wires going through door or hatch gaskets, and didn't have to worry about mag mounts scratching the roof. I've got the monster sun roof with retractable sunshade, so I'm not sure how much room there is between the headliner and the sheet metal in the back should I decide to punch a hole for an antenna.
David, ky7dr

Click to expand...

Send a PM to stealthtdi, he does the ham thing and has come up with some very ingenoius installs.

Wow! I have never seen so many of us posting at the same time!
I have a FT-1500m mounted on the side of the console next to my right
knee, but it does get in the way at times. Good luck with Hamming in your VW!

Dave
ND8Y

At some point I am going to install a 2m-440 radio in the trunk with a remote head up front somewhere.

Ray K1XV

k1xv said:

At some point I am going to install a 2m-440 radio in the trunk with a remote head up front somewhere.

Ray K1XV

Click to expand...

Excellent idea! I am thinking of hanging the main part from the bottom of the hat shelf so that it is out of the way. That will also keep the coax length to less than 4 feet or so and coax RF losses to a bare minimum.

And guys, don't waste your time trying to improve the factory tuning on a dual band antenna, if the SWR is not already below 2:1 right out of the box, find out why and fix the reason. When you adjust one band you disturb the other band and you can end up chasing your tail for no reasonable gain. If the SWR is under 2:1 when first installed, just run it and know that you are doing just fine. BTW, the antenna manufacturers don't even include instructions on tuning a dual band car antenna, nor do they recommend the operator try to do so.

Anyone know the formula to figure the loss difference between 2:1 SWR and 1.5 SWR in 4 feet of coax assuming 144 and 440 MHz?

Bill

40X40 said:

And guys, don't waste your time trying to improve the tuning on a dual band antenna, if the SWR is not already below 2:1 right out of the box, find out why and fix the reason. When you adjust one band you disturb the other band

Click to expand...

In my experience, I've found a good dual band 2m/440 antenna to be generally good right out of the box and no need to tweak anything. For those I have tweaked slightly, the 2m side will generally be more sensitive to tuning (higher Q) than the 440 side will be. The tuning on 440 will generally be fairly broad and won't be affected much by changes made on 2m.

My favorite 2m/440 dual band antenna is the old Larsen NMO 2/70 dual bander with the fully encapsulated coil. This antenna has been on the market for at least 20 years. I've tried using the open coil version (single rod, w/coil formed in the rod, looks like a cell phone antenna) and had problems with it. The coil would whistle at highway speeds and anything you put around it or in it to stop the whistling would also affect the tuning. Cell phone antenna often had a piece of foam in the coil or a piece of heatshrink tubing around the coil to prevent vibration/whistle. I found I was best off to use the older fully encapsulated coil design instead.

The only antenna mount I'll do on any of my vehicles is an NMO style thru the roof. It makes for a clean professional installation and performs well. I have an NMO roof mount and Larsen NMO 2/70 dual band antenna on my 02 Golf.

I'm thinking of doing a 2m/440 mobile install in my 05 PD Jetta Wagen after I get it back on the road. It's been dead since the July 4th holiday weekend after it suffered a timing belt failure. (a long story) The car is at mrchill's shop in Braintree MA getting a new engine and all performance upgrades we can do while everything is apart. We're creating an Uber-Wagen and it really needs a radio install. I expect to have the car back in time for TDIfest.

Dave,

Agreed. Dual band antennas should be good to go out of the box. Sometimes I run into a ham that seems to think he simply must have a 1.1 to 1 SWR or the world will end....

Bill

WOW!

Not sure how I missed this topic. KE4WMF here. How did the installs mentioned above go? I'm working on a few station improvements. I've been off the air for a while due to an intermittent radio problem (worked fine when the car was stopped and ready to troubleshoot). I finally isolated a faulty speaker. I'm glad I didn't need to replace a discontinued transceiver, especially since this particular radio fits in the ashtray. Anyway, I'm back in business. I upgraded my front dash speakers and actually have routed ham radios to the factory door speakers. The stereo still sounds good and the ham sound is definitely improved.

Here's a photo of my install:



Here's the stuff under the seat:


The antenna farm:


Anyway, I just wanted to talk HAM without starting a new topic. THIS topic seems like it has room for more discussion since at least three of us are (were?) considering installations or upgrades. So how are they going?

73,

Scott

I just picked up my 2002 Jetta, and looking for places to mount the radio. Considering making a mount to hold it above the front center AC ducts, as I have a 2DIN stereo thus no cubby.

Going with a Larsen trunk mount, I can't bring myself to drill holes in my car :/

I'm curious as to other locations people have mounted the radios, as it seems that every place I look in my car there are airbags :/


Rob
KC2EMA

edit: I suppose just picked up is getting old, I've had it for about a month now

w8dug here

Greetings, On my 01 Jetta TDI, I ran a mega supply line straight from the battery along the inner fender then under where the hood closes by the windshield in the seam , then into the door jam and down inside the trim to under the kickboards all the way into the trunk. I'm running an FT100 D in the trunk with the remote control head (and remote speaker under the armrest) attached to a small metal bracket bent to fit the bracket. I also made it bend to just the correct angle so it fits inside the air vent above the car radio closest to the driver. Easy to control while my hand is on the wheel. It's a very nice look actually. I then just use the floor and windshield vent. It has worked flawlessly for me for several years now.
The antenna's, one for UHF/VHF and one screwdriver for HF are on trunk lip mounts. One on each side.
Hope this helps,
73

w8dug here

One more thing, I'm using a radio shack 2mtr antenna that works excellent on 440mtr.It must be either 1/2 or 5/8 wave but about the length of a 11mtr cb antenna, some 50" or so,

I forgot to mention one thing I like about working HF in my car: All I need to do is slide the ashtray out toward me and it places the remote display and tuning knob just inches from my knee. I can spin the small knob without removing my hand from my knee. This isn't too different from my usual driving position.

BTW, here is some support for drilling in the roof:



The chart is by Larsen and is based on 800-MHz. I'm not sure if the losses are the same, better, or worse at 144-Mhz or HF. It's amazing that there seems to be very little difference in the losses between drilling in the center of the trunk and mounting on the trunk lip. Makes me wonder if punching the hole is worth it.

Stealth TDI said:

I
BTW, here is some support on drilling in the roof:

The chart is by Larsen and is based on 800-MHz. I'm not sure if the losses are the same, better, or worse at 144-Mhz or HF. It's amazing that there seems to be very little difference in the losses between drilling in the center of the trunk and mounting on the trunk lip. Makes me wonder if punching the hole is worth it.

Click to expand...

I think what we need to see is a polar plot of the radiation pattern at each antenna location. It could show us a lot more of what's really going on. My favorite location is the reference antenna location on the roof. My second favorite would be the center of the trunk lid.

I've tried glass mount 2m and 440 antennas on past vehicles of mine (gassers , long before TDI) and had poor performance. Switching to a rooftop NMO mount and Larsen dual band antenna worked far better plus you have many more antenna choices available with an NMO mount.

Good luck.

KO6GT here

The 75X lug is the way to go. A bigger issue, for me anyway, is where to mount a rig. I always had multiple rigs in my SUVs, but there is just no room for anything but an HT in these cars! The ham world cries out for a X-DIN configuration transceiver. I'd be all over one if it existed. Right now I have a RS PRO-2096 scanner mounted in a DIN slot and it looks almost factory. I'd replace it with a dual band rig if I found one that fit.

\73,
Jack
WA2OLZ

Greetings - does anyone know if the Sirius sharkfin antenna on the JSW's is an NMO type? I could care less about the sat. radio, and wish to install my old Vertex FTL-7011 UHF inside somewhere.

Greg