Ham Radio on a Monaco RR8R Chassis or?

[deSanford]

Installed my rig in the Monaco Cayman 2011, and when transmitting the turn signals flash on the dash. I'm using a SGC 500 watt auto tuner feeding a Shakespear Marine VHF 23 foot vertical. Transmitter is a Icom 7000 feeding a SGC 500 watt cube amp. RFI to the dash lights happens even using low power 100 watts.

[smiller]

RFI can be nasty to troubleshoot but I'd start with the basics... do you have a good low impedance ground from the autotuner and rig to the chassis? The ground connection should be heavy braid or better yet copper ground strap, not a wire. Also is this for HF? If so an antenna designed for VHF is probably not the best choice. Lastly I think I'd stay away from that amp, high power is just asking for problems in a mobile environment even with a good installation.

[mudpuppy]

I had some RF issues with my install which is a Kenwood 480HX driving a Tarheal screwdriver antenna. I placed a 1 to 1 balun at the feed point at the base of the antenna and solved a lot of my issues. I also insured that the base of the antenna, as well as the radio is grounded to the frame.

[deSanford]

I made a mistake it is an HF ant. low band 10-160 meter vertical. The radio is NOT grounded at the radio's ground "post". I thought that by connecting the 12 volts DC to the radio it would be grounded internally via the negative 12 volt connection. I will run a ground strap from the radio's external frame to the MH's chassis. The SGC tuner is grounded by a 1" wire braid to the MH's chassis. The frame that the Shakespear HF Marine antenna is mounted too is also grounded to the steel frame around the front cap of the MH and also a 1" braid is going to the SGC ground terminal. If the above doesn't work I will look into the balun. Going down the hiwy the ant. in the down position acts like an end fed wire. The SWR is 1:1 on several of the HF bands, but on 40 meters the SGC is having a tough time. The SWR goes down to about 2:1 then creeps up. The tuner then tries again, but to no avail. NO match with the ant. in the horizontal travel mode about 18" above the MH"s roof. Thanks very much for the input. deSanford W6YY

[deSanford]

Good news .......I grounded the radio to the chassis, and NO more RFI. All the dash lights and turn signals do not light up when I transmit. The antenna system now works so good that I took two first place finishes in the RF SHOOT-OUT at the Quartz-fest ham radio desert rally. Monaco's Roadmaster chassis makes a great counter poise. Thanks everyone for all the good advice. deSanford PS joined the Good Sam Hams. They help raise money for the dogs for the deaf.

[smiller]

Great news! As you just found out the DC power supply ground often isn't a very effective RF ground.

[wa8yxm]

This is fairly common if the dash lights or the tail (turn) signal lamps are LED.

I have an LED indicator in my radio room that flashes (I run 100 watts max) the problem is you have a wire that runs all the way from the front of a motor home to the rear, This is what, about 10 meters of wire, It acts very much like an antenna, Even on 80 meters it's enough to light up an LED.

Now incandescant lamps take more power but then you are running more power. (I[m only pushing 10)

Of course I push that hundred watts into a hundred feet of long wire (That makes up for some of your power)


Try running PSK or other digital modes.. My last PSK contact was with Hungry,, Power, 30 watts on my end. (his too i think) I'm constantly amazed at how little power I need to do the job digitally.

[Diplomat Don]

Do you have remote keyless entry. If so, I would take a look at the Trimark keyless entry unit under the dash. It flashes the lights when you lock and unlock the coach.

[deSanford]

Don on my couch I'm lucky they even put a lock with a key much less a "keyless" entry. I would have to have paid about $100,000.00 more to get features like that. Yes I learned a lot Smiller about DC grounds. I'm taking my coach to the service center as the coach batteries are not getting a charge from the alternator when I'm driving. The chassis batteries are and that is normal, but even when they are FULLY charged the sensor that is supposed to tell the solenoid to now give a little juice to the coach batteries isn't doing its job. After I get that fixed on to other items that I need to address. Looking forward to a non event trip. deSanford