[Antennas] Dual band mobile

2003年12月24日 20:30:13 -0600

That's it, a collinear, 5/8 over a 1/4. What I've done so far is 
drill and tap the trunk lid mount and add 6.25" grounded rod an 
inch away from the antenna. The idea was to make the antenna an 
open stub j-pole on 70 cm. 
The swr on 70 cm has improved and and the swr on 2 m is still 
below 1.3 across the band. The antenna seems work on 70 cm, at 
least it radiates better than a dummy load. I've only had the 
antenna back on the car for 2 days and haven't really had a 
chance to see what it will do. I haven't had a chance to try 
tuning the length of the 1/4 wave stub either.
Next project - figure out how to identify the 70 cm side of the 
crossband repeater since the FT-8800 CWID doesn't work in 
crossband repeat.
On 9 Dec 2003 at 19:37, John Webb wrote:
> Mike,I may be thinking of another antenna.Isn't the one you have a colinear?
> has a solid rod then a abt3/4 in load and a whip ??? If that is the one you
> have then the lower rod is 1/4 on vhf and 3/4 on uhf...73,john
> ----- Original Message ----- 
> From: "Mike Miller" <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, December 09, 2003 6:44 PM
> Subject: [Antennas] Dual band mobile
>>> > I just bought a dual band mobile that will be replacing the 2 m
> > mobile in the car. I'm currently running a Hustler CGT-144
> > antenna, and I'd hoped that I might get away with using it on
> > 440 for short range crossband repeating, but the swr is at least
> > 2:1 on 440 so that's out.
> >
> > What would be my chances for success adding a 1/4 wave whip at
> > the base of the CGT-144 sharing the transmission line?
> >
> > The next two options should work but I'd like some input.
> >
> > 1. Use a diplexer and separate 440 antenna. Who makes a good
> > 2m/70cm diplexer? I already have another antenna I could use on
> > the 440 side.
> >
> > 2. I could look for a dual band gain antenna to replace the CGT-
> > 144. Which dual band mobile antenna would come close to the CGT-
> > 144 on 2m? Hustler claims 5.2 db(?) which might be reasonable
> > for a 7 foot collinear.
> >
> > Thanks,
> > Mike kc9doa
> >
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> >
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