Ham Radio?

Don't know...you wanna be a guinea pig on this one? :idea:

Seriously, I have not installed my Kenwood TM-V7A in our car yet. I have had too much going on lately (as a matter of fact, I can't read PriusChat.com everyday! What a pain!). I would imagine that the "sensitive circuits" would not be fried, as auto manufacturers test their electronics using high RF fields and possibly intense high voltage static discharge. Their could be a possibility that control of the car could be affected by RF. To date, other hams I have contacted (from the YG Prius sites) have not indicated any problems. Toyota does recommend in the manual that they should be contacted before any "Two Way Radio Installations" be attempted. But, they don't give a contact name, phone #or email address for this information.

What bands are you planning to work? I am right now just planning 2M/440 (6M with my VX-5, which is only 5 watts max if I get the time)

Where do you plan to install your radio? I was thinking of the main unit in the rear area near the 12 volt battery, with the control head under the dash, and the microphone stored in the center console.

Any ideas for the antenna? I have a mag mount to check out antenna locations, but may settle for a hatchback mount to put the antenna at the rear as high as possible on the car (and still clear the garage door opening here at the house).

Keep us posted on your efforts. I will do the same, and since we have a sub topic for Ham Radio, this would be a good area to post messages!

73,
WØBEV

 

I'm still waiting for our Seaside Pearl, pkg 6 or 7 to arrive (5 months, 5 days since placing the order), but I have done some research on other Prius lists. Most of the posts refer to the 2001-2003 models.

I've not seen any posts about a ham radio causing problems with the car. Several people report that 2m/70cm radios work fine. HF radios seem to hear a lot of RFI from the car electronics.

Once your mount your radio and antenna, I'd measure the SWR and make sure it is reasonable, maybe 1.5 or less? You want that 50 watts being radiated by the antenna on the outside of the car, not by the coax inside the vehicle.

My ideas for mounting the radio are similar to Opusnugen. I think there is an appropriate spot under the rear deck on the driver's side opposite the 12 volt battery. That seems like a good place, and easy to connect to the accessory (12 volt) battery.

There isn't much room on the dash or under it, so I'm also going to experiment with placing the control head above the rear-view mirror.

Mounting the microphone on the center console makes some sense to me also.

As for the antenna, my first guess is a glass-mount dual-band Larson on the rear quarter-window on the driver's side, although the hatchback window is an option too. I don't think I'm ready to start drilling holes in the roof.

Hopefully this helps, but since I don't have the car yet, YMMV!

73, Steve (N9IP)

 

Ham Radio in Prius

I have a 2004 Prius. I intend to be able to use HF from the car someday.

I removed one on the towing brackets under the car in the rear near the bumper and had a metal shop make me a trailer hitch receiver that I bolted in its place. I use a High Sierra screwdriver antenna, and an Icom 706IIg at 70 watts on CW. I use a mag mount ant. for 2m/440. For now, the 12 v. jack inside the car powers the radio.

The RFI on all the HF bands makes the radio unusable it is so bad. Only the very strongest signals can be heard, and its still a mess. An MFJ noise canceler didn't help. I emailed a ham in Japan, who asked around and found Mr. Takeda who uses ham radio in his 2002 Prius. With that advice, I installed an Amidon common mode choke at the antenna, at the input to the radio, and on the power cable. I ordered 16 split ferrite beads from Newark and placed them on all the wires I could get to from the inverter, and then on every wire I could find under the rear compartment--the brake controller and generally anywhere I could find. I took a 3 KV 0.01 Mfd capacitor and connected it between one of the fuse bolts in the orange battery disconnect plug in the back at the HV battery, and ground. I bonded the hood to ground in 2 places with braid, and bonded the inverter cover to ground, too.

When I get the time, I intend to supply a better RF ground for the 12 V. system at the battery, and bond the engine and tailpipe to ground, too. So far, the noise reduction has enabled me to have CW QSO's on 40 and more successfully on 20. The engine coughs when I transmit on 30, so I quit that for now. Someday I'm going to pay the Prius mechanic to take apart the dash to install more ferrite beads on the computer wires. I'd sure love to get into the inverter and add some bypass caps.

I get no probs on 2 M or 220.

More if and when I can reduce the RFI some more.

Regards, John, W9NET

 

I appreciate your reply. Everything is a trade-off, but its unlikely that a rescuer would get a shock from removing the orange battery disconnect plug. The 3 KV .01 cap is mounted in the connector and the ground wire is run to the other lead coming off the capacitor with everything insulated. Common mode filters and bonding the sheet metal ought not to be an issue. If we could put men on the moon 30 years ago, there should be a way to reduce the EMI.

Regards, JL

 

Re: Ham Radio in Prius

John,

I assume that you connected the 706 to the 12V connection in the engine compartment.

Where is the plug to route wires through the firewill?

73 =paul= W8KC

 

Nope. For now, I simply use the 12 V. DC socket to supply the 706. The cable is wrapped in an amidon toroid. I tried a separate battery (a big gel cell) isolated from the car's 12 V. system and there was no difference in noise amplitude in the receiver.

Regards, JL

 

I ran 150 watts output on 2m and enjoyed QSOs on my 1 hour commute for a week or so - I didn't notice any problems with the RF getting into the 2005's electronics. The antenna, an MFJ-1422, was mounted high on the passenger side of the hatch.

Ultimately, I melted the antenna...

 

I haven't, and don't intend to try HF. However, I poked the obligatory hole in the roof a couple of weeks after I got my Prius. The antenna feed for a 2M-440 dual band antenna comes out from under the roof liner at the top of the rear hatch. This feedline runs down along the left side of the left rear passenger seat and under the drivers seat where an IC-2720 is sitting right on top of the NAV unit. The control head fits nicely in the small storage compartment under the CD player (although the compartment door won't close with the control head in place). The cable to the control head runs up under the back of the bottom center console cover (easily removable) and enters the storage compartment through an "after-market" opening in the lower rear of the storage compartment. Plenty of extra space behind the contol head accomodates the excess control cable, which is handy if you want to pull out the control head for a closer look - appealing to us visually-impared. The mic is attached to the main body of the radio, comes up along the right side of the drivers seat and normally resides in the large cupholder. A small external speaker lives in the front cup holder. Power to radio is supplied via fused zip cord attached to the 12V battery and attaches to the radio with powerpole connectors.

It all works just like it should and nothing untoward has been experienced on either band at any power level. I have been using this setup for over 4 months.

 

Hi

I just read you post, and I am having the same issues with RFI. I have the same radio, with a hatch mount Hamstick. I bonded everything, except the exhaust.

I used 31 mix beads on most of the leads going in to the DC-DC converter, and managed to get the RFI to S6 or S8 except on 15 and 10 where it is S1

I have discovered, by asking an EMI engineer, that the Prius converter needs to have 0.1 UFd disk ceramics installed as shunts across all of the cables going in and out of it. Apparrently the DC - DC converter produces square waves with really nasty harmonics.

I was wondering if you have thought of getting/installing a larger battery to power your ICOM?

73

VE3XKD

 

Will the hatch mount, which bites into the hatch when you tighten the screws, cause rust over time?? Or is the hatch made of aluminum like the front hood?

And, did you just route the coax over the rubber seal? Any problems with it leaking?

I just got a FT-8900R with a SB-15 Comet ant. and hatch hood mount (Diamond Y400C?) and trying to figure out where to install it. I am using a 2m/440 mag mount now w/ the rig sitting on the seat for now.


BTW, the ARRL has some info on RFI in cars:

http://www.arrl.org/tis/info/carproblems.html