Replies interspersed

"starman" wrote in message
...
Dave wrote:

Starman,

I am no longer intending to use a folded dipole, or a dipole of any
kind. I am currently planning to connect the conductors at the far end of
the 300 ohm twinlead but only connect one side of the near end to the
300/75 ohm matching transformer. Will this not work? I don't need
perfection, just reasonably good (I think.)

Thanks,

Dave

So you're going to use the twinlead as if it was a single wire. In that
case, you might as well connect the two wires in the near end too. There
isn't any advantage to keeping the wires of the near end seperated.
Connect the twinlead's near end to one wire of the high impedance side
(300-ohm) of the matching transformer (balun).

I'm not clear on this. It sounds like you are saying to make a loop out of
the twinlead, only to connect both near ends to the center conductor of the
300/75 ohm matching transformer (I guess.) Is that right? What would that
accomplish?

The other wire on the
300-ohm side should go to a ground rod, IF you're building the antenna
design on the website I gave you.

Do you mean the low-noise inverted L? If I did that, one leg of the L would
be hanging near my A/C compressor, which I fear would induce a great deal of
EMI. That's why I went back to the higher-up random-wire idea.

Otherwise connect the remaining
300-ohm wire to the shield of the coax.

Ramaining 300 ohm wire? You just lost me. When I connected the two 300 ohm
twinlead conductors together on the near end, I came up with one wire, which
I already connected to the pigtail going to the center conductor of the
300/75 ohm matching transformer. What remaining wire? Where did I go
wrong?


This will require some kind of
adapter, if the balun has a threaded female F-connector for the coax on
the low impedance side. A standard coax inline grounding adapter (block)
would work. These are made for connecting a ground wire to the coax
shield in a TV installation. This adapter has a female F-connector on
each end and a grounding screw on the outside of the 'block'.

I *think* I understand up to this point.

Connect
the remaining wire on the 300-ohm side to the ground screw on the
adapter block.

Is this the same "remaining" wire as before? Do you mean to connect
whichever side of the antenna I grounded to the ground screw on the adapter
block?

If you use this kind of adapter you will also need
another adapter with a male F-connector on each end to connect the
ground adapter block to the threaded female side of the balun. You might
be able to find a coax grounding adapter which has a male F-connector on
one end and a female on the other end, along with the grounding
terminal. Then you wouldn't need two adapters.


Have some trouble following this, but let me see if I have it at the end.

The center wire of the coax goes to the low impedance side of the balun
which is the center hole of the threaded female F-connector on the
balun. The coax shield connects to the outside threads of that
F-connector, which would also go to the ground rod from the grounding
adapter, if you're making the website antenna.

All of the above assumes you're using a standard TV balun which has a
threaded female coax F-connector for the low impedance side and two
wires (pigtails) on the high side. You should install a male F-connector
on the balun end of the coax. In the previous post I advised against
using a TV balun because it will most likely attenuate signals below
about 10-Mhz. This means the lower shortwave bands and also the regular
AM(MW) band would be somewhat weaker but this might not be a problem,
depending on what frequencies/bands you want to hear best.


Okay, let me see if I have this right. 50' of 300-ohm twinlead, conductors
connected at the far end to make a 100' loop. Connect one side of the near
end to the pigtail of a 300/75 ohm matching transformer that goes to the
center conductor (if I'm using TV matching transformers). Connect the other
side to the pigtail that goes to the coax shield on the other side of the
transformer. Connect the female F side of the 300/75 ohm matching
transformer to the male F connector on the coax. Coax goes down side of
house where it uses a male connector to connect to a F/F adapter mounted in
a grounding block, which is mounted on the grounding stake. On the other
side of the grounding block, male F connector on other side of the same F/F
adapter attaches to coax which goes underground around the corner of the
house (and past the A/C compressor) to my window and the radio. Is this
basicaly it, or have I gone totally off-center?

Sorry if I am making this complicated. I easily get lost in all the
male/female F connector to balun business. Main question I *think* I have
is- should I use the twinlead as a 100' loop, or a 100' random wire? And if
it is a loop, do I ground one side of it?

Thanks,

Dave