TIL mounting antennas

[Fummins]

Or something like this to spread out the load? Maybe one with 3-7 suction cups!

[Wallythacker]

How about a magnetic antenna like on some WW2 aircraft? Then you would also need a good antenna tuner with high-voltage capacitors to prevent arcing. In these parts with all the interference from LED lights and cheap non-transformer PSU's, magnetic is the way to go.

It's not so easy to get good capacitive interaction with a magnet mount. I would prefer to have a resonant antenna without using a tuner. The efficiency of a mobile antenna can be as low as a few percent and given a choice, I'd rather not to loose any more efficiency than possible.

What if you rigged some sort of brace from the roof extended out to the antennae? To stop the base from flexing the hood.

That might be the best idea. It's not so difficult to string some thin stainless wires around the hatch hinges and attach them to pretty strong nylon filament guy wires. That, along with some sturdy sheet metal backing to spread out the load might be the answer, I have to think this thru to make it easily removable for the car wash.

I, get a load of this, discovered a neat gizmo that uses the CD slot to mount a device to hold the remote head of a radio transceiver. About 20 years ago the radio makers decided to split the RF section from the tuning section of radios. The RF section is big a bulky thing while the tuner/controls are only 1" thick.

Well as soon as the mount arrived at my door I realized it could easily hold the head of both radios I plan to run in my car, an all band all mode HF radio + tri-band V/UHF radio. I have to dig out a small piece of aluminum from my scrap bin and with an hour work and some epoxy a dual head mount is made. I can hide the RF parts under the front seats.

Or something like this to spread out the load? Maybe one with 3-7 suction cups!

They have 4 suction cup models,
But see my comment above about getting enough capacitance without resorting to extra crud,

[foama]

It's not so easy to get good capacitive interaction with a magnet mount. I would prefer to have a resonant antenna without using a tuner. The efficiency of a mobile antenna can be as low as a few percent and given a choice, I'd rather not to loose any more efficiency than possible...

In these parts there are high interference levels, in fact in many areas noise floor has gone up some 30 to 40 dB durning the last decade! Otherwise said, interference level has increased up to 40 000times. Years ago, when the first powerline WLAN extender system was set up for trial in a London hotel, ham operators as far away as Bulgaria complained about the sharp increase in noise. Now these gadjets as well as LED lights and power supplies without transformers are almost in every town.
For those reasons, many here are using magnetic antennas. That helps because magnetic portion of RF has less interference, because most interference comes from the electrical component of the signal. A magnetic car antenna is merely a small loop rather than a rod, takes up less space and won't blow away. Of course it is resonant, otherwise it wouldn't work.

[Wallythacker]

What if you rigged some sort of brace from the roof extended out to the antennae? To stop the base from flexing the hood.

The more I think on that the more I like it. It can be as simple as 100lb test braided line, nearly invisible from a distance

In these parts there are high interference levels, in fact in many areas noise floor has gone up some 30 to 40 dB durning the last decade! Otherwise said, interference level has increased up to 40 000times. Years ago, when the first powerline WLAN extender system was set up for trial in a London hotel, ham operators as far away as Bulgaria complained about the sharp increase in noise. Now these gadjets as well as LED lights and power supplies without transformers are almost in every town.
For those reasons, many here are using magnetic antennas. That helps because magnetic portion of RF has less interference, because most interference comes from the electrical component of the signal. A magnetic car antenna is merely a small loop rather than a rod, takes up less space and won't blow away. Of course it is resonant, otherwise it wouldn't work.

Good lord! Noise floor of 40db? You're only going to work stations down the street from you. The worst noise floor I have is about 6db @80m. 40 & 20 are surprisingly quiet.

You have all those restrictions on modifying cars that we don't. So what are the rules about mounting masted or guyed antennas on smaller cars? Do you lose the type certification because technically all glass these days are structural members ? This is obviously for glass mount antennas but what about large antennas generally?

[foama]

The more I think on that the more I like it. It can be as simple as 100lb test braided line, nearly invisible from a distance



Good lord! Noise floor of 40db? You're only going to work stations down the street from you. The worst noise floor I have is about 6db @80m. 40 & 20 are surprisingly quiet.

You have all those restrictions on modifying cars that we don't. So what are the rules about mounting masted or guyed antennas on smaller cars? Do you lose the type certification because technically all glass these days are structural members ? This is obviously for glass mount antennas but what about large antennas generally?

The noise level is not 40dB, it has gone up that much. Noise polution is currently S7 to S8.

The laws about an antenna on a vehicle say, no restriction of driver's visibility, but a rigid radio antenna on a front fender is tolerated.

The law says, the antenna rod or whip must not be able to touch anything or any person outside of the cars perimeter, no matter what forces are applied. That for example includes wind of 200km/h as well as inertia from a serious crash into you name it.

[Wallythacker]

The noise level is not 40dB, it has gone up that much. Noise polution is currently S7 to S8.

The laws about an antenna on a vehicle say, no restriction of driver's visibility, but a rigid radio antenna on a front fender is tolerated.

The law says, the antenna rod or whip must not be able to touch anything or any person outside of the cars perimeter, no matter what forces are applied. That for example includes wind of 200km/h as well as inertia from a serious crash into you name it.

Very interesting. I see how a rigid Comet/Diamond dual band antenna would likely be fine. I suspect that enormous monstrosity in, what, Spain? would get you pulled off the road.

[Wallythacker]

I'm still plugging away looking for the best compromise with my antenna.

My current attempts are using a slim all band antenna that uses a wander lead. It means I have to stop to change bands but maybe that is safer than playing with tuner buttons However, when fender mounted the antenna tip is about 9-10 feet from the road. There are lots of overhangs that are less than that. My tourist McDonalds is only 9 feet even.

When I use the mag mount my antenna tip is likely 12-13 feet from the road. Even worse problem for overhangs.

[Eggman]

With all this radio equipment, have you noticed any interference with your vehicle electronics?

[Wallythacker]

With all this radio equipment, have you noticed any interference with your vehicle electronics?

NONE! I don't expect any interference from my HF radio, 1.8-54 MHZ TX but I have experienced odd stuff in the past with my dual band radios which TX from 144mhz-465mhz.

Both radios have been used in full power mode which is 100 watts for the HF and 50 watts for the dual band. Those power levels are enough to give someone serious RF burns if they grabbed the antenna during transmitting

[Wallythacker]

Continuing with my quest to find the The best antenna for my Mirage I acquired some interesting stuff in a prior trade deal that I thought might work.

The screwdriver antenna I had on my hood is a great high performer but has some faults. Its large and heavy. I've been reading more than one guy has bent up his sheet metal. Another concern I have is theft. Those antennas sell for $1000 and might be a target. I do have a quick release which means if I don't remember to store the antenna every time I leave the car then it will easy to be swiped. The last concern is time. It's a great antenna but tuning it can take up to a minute in some cases. And it's dangerous to attempt anything band related with this antenna while on the move.

So here's candidate #3. Advantage. The bands I want to use are immediately accessible. The proper resonator is used automatically without intervention on my behalf. Not that I would, but if I were talking on the go and wanted to see what was happening elsewhere I could safely switch bands immediately. I can remove resonators if I decide to just have 1 or 2 bands available, and depending on conditions that might be enough. But fugly.... oh boy.