[AMRadio] Re: new antenna and matchbox a bust.


Geoff/W5OMR ars.w5omr at gmail.com
Tue Jan 30 23:53:02 EST 2007


Brett gazdzinski wrote:
> You guys are mixed up.
> I had 50 feet each side on the antenna, for 80 meters,
> about 65 feet each side would be resonant (roughly), so
> I am 15 feet short.
>   

I've found out from experience, open wire line forgives sins of the 
antenna.  So far, so good.

> I then had 42 feet of open wire line running down to almost 
> ground level, where it went into 2 runs of RG214, each leg
> of open wire line was tied to the center conductor of each
> coax cable.
>   

That looks ok, so far, as well.

> It had the shields soldered together, ran through a PVC pipe
> with the ground wire and other coax cables, into the basement.
>   

Ewwww!  Open wire/ladder-line/balanced line likes to be isolated.  RF 
could be induced into the other wires and lines.  Ground loop nightmares 
abound.
(my personal opinion)


> On the other hand, connecting the open wire line to the RG214,
> center and shield, into the heathkit tuner, seems to work well.
>
> I assume some of the open wire line acts like the missing 15 feet,
> and/or carries the bad voltage and current points, not the coax.

I suspect the latter.  Regardless of the length of the open wire line, 
that's still just the feed line.  The load/antenna *should* still be 
resonant for where you want to operate. 
Again, I say that open wire line 'forgives' the sins committed on the 
antenna.

--
73




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