Okay, so you're saying in my picture where I have it labelled to use 75 ohm coax, you would use 50 ohm coax to feed both antennas for the 1/4 wave and 1/2 wave pieces etc?

Then the input of the coax switch would be 25 ohms?

If I use two 1/4 wavelength pieces of 75 ohm coax in parallel between the rig and the coax switch, that will be 25 ohms at the antenna switch?

Thank you very much.

http://i49.tinypic.com/2rhlaba.jpg

I attached a "picture" of what I think you described.

Could I use a regular two position SO-239 antenna switch and just parallel the 1/4 A to B jumper in the same PL-259 connector as antenna 1 on connection A and the other end of the same jumper in the same PL-259 as antenna 2 on connection B?

I don't understand why you said drop to 25 ohms right before the antenna switch?

Wouldn't this work fine with 50ohm coax between the antenna switch and the radio?

I know I can do something like this for in phase:
http://i50.tinypic.com/2elqk9v.jpg

How would you recommend feeding the two antennas out of phase by the flip of a switch? Can you draw me a picture of that similar to what I posted above?

So you think go with two 1/4 wave whips and space them 1/2 wave apart? about 39" or so?

Could be a loose connection.

Do you have an external SWR meter? I would check with that and see what it says. Then see if you have a loose jumper, antenna connector, moisture problem etc.

Thanks guys.

AB3OL,

If you put something vertical up for FM lookup my call and email me and we can test out your range when I am in the area.

I have a TE Systems repeater amplifier, and receive is attenuated when the amplifier is in line versus when it's not in line.

Is this normal since the amplifier has no relays to take it out of line or should it not be attenuating the received signal strength?

Thank you for your helpful responses!

So I would add a second antenna, same length as my existing 1/4 wave 2 meter antenna and put it 1/2 wavelength away (38" I guess)?

Then I would have a coax switch to switch between the two fed in phase for broadside +3db radiation or 180 degrees out of phase (extra 1/2 wave to one antenna) for end fire +3db radiation?

Should I use 75 ohm coax to achieve this? Could you point me in the right direction as far as achieving in phase and 180 degrees out of phase?


I'm not really opposed to a fixed 3 element yagi on the roof, either, at least to try it. I was thinking with that I could stick a director and reflector on the roof and wouldn't have to run coax or even punch another hole if I use a mag. mount for those. Not sure if they (the director and/or reflector) would work better grounded to the car body or insulated from.

Thanks for the info.

I am just looking for a new approach to 2 meter FM simplex while driving the vehicle, not just moving back and forth a few feet.

I currently have a hitch mount mast system and 4 element quad etc. I can setup while fixed for contesting.

I am after something permanent to play around with for mobile contacts on 52.

Would you mind explaining the "broadside" and "end-fire" you mentioned?

I know, while it doesn't work properly at 27 MHz on a vehicle due to space restrictions and maybe a lack of an earth ground, a lot of CB operators use two antennas (one on each mirror) fed in phase for a bidirectional pattern in front of and behind the vehicle.

I'm not sure if that's feasible at 146 MHz and really provides any gain or not? I was thinking along the lines of a mobile 3 element yagi just by adding a director and reflector to my existing 1/4 wave but I don't really see where anyone else has done it.

I replaced the driver transistor and the amplifier seems to be working perfectly now.

Thanks everyone!

Thank you KA5IPF!

I appreciate it very much.

Thanks for the links, I'll look through those.

I know horizontal is normally used for SSB, and vertical for FM and a loop is normally used for mobile SSB work.

What I am after is more range.

Primarily 2 meter FM simplex. Maybe using the cars body for the bottom half of the elements and making a 3 element fixed yagi. Say a 20" reflector and a 18" director in front of my existing 2 meter 1/4 wave whip? Wasn't sure if anyone had any experience/input for something like that?

Then I've also seen the yagis hunters use for dog tracking that can be mounted and used horizontally and rotated inside the vehicle. I wouldn't be opposed to something like that either.

Does anyone have any experience using a yagi or directional/gain antenna on a vehicle?

I have a hitch mount and mast I use to mount a quad for stationary contesting etc.

I am looking for something to improve 2 meter performance, primarily FM but maybe SSB while able to move the vehicle.

Hunters use an antenna for tracking their dogs that is similar to a 3 element 2 meter yagi (maybe 155 MHz or so) that can be mounted horizontally and rotated through a hole drilled in the roof or with an electric motor (rotator).

Some CB operators have used a director on the front of the vehicle and a reflector on the back to make their SUV a 3 element vertical yagi.

I was thinking of doing something similar. Maybe an inch or so shorter magnetic mount director in front of my 1/4 wave 2 meter antenna and an inch or so longer 2 meter reflector on a magnet (neither having coax) behind my 1/4 wave antenna. The only way to change directions with this would be to move the vehicle.

Does anyone have any experience / advice?

Another radio within walking distance cannot hear you?

You should be heard on a nearby radio even WITHOUT an antenna connected.

Check for power output at the radio. Check the microphone etc. Try FM or CW instead of SSB.

Thanks.

What do y'all think caused the driver transistor to open like that?

I appreciate it.

Is there much chance of finding one at a hamfest? I was thinking about waiting and seeing if I see one there, but I could go ahead and order one online if y'all think that's pretty much impossible.