Having recently passed my foundation exam I'm considering fitting a 2m / 70 cm mobile radio to my Yeti, probably something cheap and cheerful like an AnyTone 778. My problem is that I'm a bit of a perfectionist and don't like bodge jobs, which means that not only has this got to look as close to an OEM fitment as possible, it's also got to leave absolutely minimal trace if I decide to remove it later. To that end I'm wondering if you've fitted either an amateur radio, scanner, or any other type of transceiver to your Yeti, what went well, and what you'd do differently next time around. Here's what I'm thinking:

 

Main Radio

 

In an ideal world I'd like one of those rigs where you can squirrel away the transceiver and just mount the faceplate on the dash, but that's out of budget right now, so I'll have to plonk the whole thing somewhere. Right now I think that's going to be the lower dashboard panel that's just ahead of the driver's right knee, underneath the light controls. It's a large area with plenty of room, should be simple to reinforce from behind if necessary, and there's easy access to the fuse box for power. Bonus: any holes I'll need to make can be covered with a discreet grommet if I ever remove the radio, and are unlikely to be seen again.

 

Antenna

 

This is where it gets tricky. In the aforementioned ideal world I'd want to mount a small whip via a right-angle bracket to the rearmost holes in the drivers side roof rail, but getting the cable up there could be a right PITA. I don't want to make new holes in the car's roof and nor do I want to compromise the structural integrity of those roof rails, but it sure would be handy if I could run my co-ax into the back of the roof rail (which I imagine to be hollow) before passing it out of the front of the rail and into a convenient grommet where the rail attaches to the top of the A-pillar. From there it's easy peasy; down the A-pillar, past the fuse box, to the back of the rig. Something tells me that I won't be finding that convenient hole at the base of my roof rails, so I'm open to ideas here.

@Llanigrahammight be one of the members able to assist.

 

EDIT / PS. 

Sorry for my ignorance i needed a reminder.  Congratulations & well done.

 

Edited 26 September, 20214 yr by e-Roottoot

Congratulations on passing your exam @muppix.

There are a few hams on here that may be able to help. My days of /M are in the distant past though. 📻

Don't think I can be much help, I'm afraid. My set up was a Motorsport UK rally safety unit that used to sit on the top of the dash, with two wires direct to the battery through the passenger door and a mag mount aerial with the lead through the back passenger door.

Hi Muppix

 

When I was gainfully employed it was in the area of EMC, RF design and Antennas.  We used to find with vehicle fits that the more effort you put into doing a neat job, the more likely it was that there would be some problem requiring you to delve in and change something !  My advice would be to do a reasonable temporary job first , and check that the DC supply is OK, the received radio noise is OK and the transmitted RF isn't getting into something it shouldn't and upsetting it. Once that's out of the way you can pretty it up and replace the gaffer tape or whatever with something neater.

 

You could consider using RG-316 cable which is thin enough to go past a rubber door or tailgate seal and being teflon based is quite tough. The insertion loss is about 0.6 dB/m at 432 MHz so it's probably a good idea to only use a short section where needed and use something fatter for the bulk of the run.

 

The coax outer braid needs a good low inductance connection to the roof/roof rail metalwork at the antenna end.  You can also do yourself a favour by placing two or three clip-on ferrite sleeves at intervals over the coax where it runs inside the cabin, as a precaution to suppress any RF on the outside skin of the braid which might cause mischief.

 

You might also consider linking across the tailgate hinges with short braided straps, as the groundplane current density will be quite high near the base of the antenna and greased pins are a bit variable at RF to say the least.

 

I would be wary of mounting anything too close to the zone immediately in front of the driver or passenger's legs, which is deliberately crushable in case of an accident.  It sounds like you had in mind something a bit higher up.

 

73's    Austin 7

 

 

My Yaesu sits on the floor in the passenger well. It is possible to thread a 6mm cable through the bulkhead if you remove the glove-box,I pulled the cable through and the fitted a plug so that I could remove the transceiver to fit in my camper van The  twig goes out through the rear passenger door to a mag mount on the roof

6 hours ago, e-Roottoot said:

EDIT / PS. 

Sorry for my ignorance i needed a reminder.  Congratulations & well done.

 

No worries @e-Roottoot and thanks for those links! Not sure how I missed those when using the internal search tool before posting, guess that's the power of G00gle for you!

 

4 hours ago, Llanigraham said:

My set up was a Motorsport UK rally safety unit that used to sit on the top of the dash, with two wires direct to the battery through the passenger door and a mag mount aerial with the lead through the back passenger door.

 

Hehehe, sounds perfect @Llanigraham - to be fair I'm not sure I'm up to that level of engineering. 😉

 

1 hour ago, g7eor said:

It is possible to thread a 6mm cable through the bulkhead if you remove the glove-box,I pulled the cable through and the fitted a plug so that I could remove the transceiver to fit in my camper van The  twig goes out through the rear passenger door to a mag mount on the roof

 

Gotcha, cheers @g7eor - my mag mount currently goes through the rear o/s passenger window which is then left open half an inch, I just don't have the heart to wind it up fully or shut the cable in the door. We get some pretty nasty weather round here and I want to keep them door seals happy...

1 hour ago, Austin 7 said:

My advice would be to do a reasonable temporary job first , and check that the DC supply is OK, the received radio noise is OK and the transmitted RF isn't getting into something it shouldn't and upsetting it. Once that's out of the way you can pretty it up and replace the gaffer tape or whatever with something neater.

 

That's a great idea @Austin 7, thanks. To be fair RF is a particular concern given where the rig will be located, right next to all the whizzy bits in the dash. My back-up plan would be to have it in the boot and run it off the cigarette lighter socket back there, since a good deal of the time I'll be parked up when talking anyway, enjoying the comforts of that leather bench with a cuppa while looking at the scenery. Either way a trial run sounds like sage advice.

 

1 hour ago, Austin 7 said:

You could consider using RG-316 cable which is thin enough to go past a rubber door or tailgate seal and being teflon based is quite tough. The insertion loss is about 0.6 dB/m at 432 MHz so it's probably a good idea to only use a short section where needed and use something fatter for the bulk of the run.

 

I don't like running anything past them seals, no matter how thin, and each join between rig and twig is bound to bring penalties. Thanks for the idea of RG-316 though, that's not something I've come across yet. Gratefully noted.

 

1 hour ago, Austin 7 said:

You can also do yourself a favour by placing two or three clip-on ferrite sleeves at intervals over the coax where it runs inside the cabin, as a precaution to suppress any RF on the outside skin of the braid which might cause mischief.

 

Will do. If I end up running the cable inside the A-pillar then I'll definitely stuff some ferrite sleeves up there, and will keep my fingers crossed that the RF doesn't set off the adjacent airbags. Could prove embarrassing ...

 

1 hour ago, Austin 7 said:

You might also consider linking across the tailgate hinges with short braided straps, as the groundplane current density will be quite high near the base of the antenna and greased pins are a bit variable at RF to say the least.

 

Now that's not something I'd considered, because I wasn't planning on using the tailgate for anything. Tell me more - is this so that I have a constant mass as ground plane instead of an unknown quantity due to the hinges? I'm not sure what percentage of total vehicle mass (groundplane) is represented by the tailgate, but like I said, it's not something I'd considered. Definitely food for thought.

 

1 hour ago, Austin 7 said:

I would be wary of mounting anything too close to the zone immediately in front of the driver or passenger's legs, which is deliberately crushable in case of an accident.  It sounds like you had in mind something a bit higher up.

 

Nope, I was thinking of the area in front of my knees, and hadn't considered the whole accident scenario. It's a good point though, thanks. I think I'll have that trial run before making too many more plans, but if you have any suggestions for alternative rig locations then I'd love to hear 'em.

 

Thanks again!