Andy wrote:
Ian,

I'll have to do some experimenting with the 300 Ohm feeder and see what
happens. The End Fed on 40m is very poor indeed. I would say unusable like
it is.

The End Fed wire at the moment is resonate on 2. 682 MHz.

The funny thing is that when I cut the wire to bring the End Fed to resonate
on 80m, no matter how much wire I cut off it doesn't really move from the
2.682 MHz. I have tried this with and with out the ribbon feeder being in
place and with coax connected direct and the braid connected to the earth
rod.

What would cause this?

I have no problem using the Analyser with my mobile and centre fed dipoles.

73 Andy


"Ian Jackson" wrote in message
...
In message , Andy
writes


"Ian Jackson" wrote in message
...
Andy, is your endfed wire the one in your other thread of the 8th June
(ie
the 80 Meter End Fed, fed with coax at the far end)? If so, presumably
the
tuner is at the shack end. Or are you feeding it from the shack end.


In message , Andy
writes

--

Hi Ian,

Yes its the same. The tuner is at the shack end (house) and I'm feeding
the
antenna with 50 Ohm RG-58 C/U coax at the far end of the garden. If I can
get it working well I will replace it with some RG-213 that I have here. I
put it back up yesterday and started experimenting again.

The End Fed at the moment has 15 feet of 300 Ohm slotted ribbon feeder.
This
is all I had left spare. One side is connected to the wire antenna and the
other side left, not connected. The coax is connected to the 300 Ohm at
the
bottom and the braid side is now connected to the unconnected side of the
300 Ohm and also to the earth ground rod.
On 80 the receive is up 2-4 S points compared with the 40m coax Centre Fed
Dipole. I have not had chance to get any actual reports on 80 yet. Maybe
this weekend.

73 Andy
OK, Andy. Noted.

I don't know if you will really improve things by using the 15 foot of 300
ohm feeder. It's a sort of a zepp, but with one side of the twin feeder
earthed. I would try disconnecting the earthed ('unconnected') side from
earth / coax braid. You can either leave it floating, or connect it to the
coax inner. It will then be approximately a quarterwave on 20m, fed in
parallel with the long wire.

Don't read too much into the excellent SWR you're getting with the tuner.
That's what the TX sees, but the tuner can't affect the SWR on the aerial
feeder. If the coax SWR is sky high (and it can be if the impedance at
aerial feed point is high), the coax losses will be much more that you
would get compared with when it is matched correctly. You only get away
with it by using the lowest-loss you can find, and keeping the coax as
short as possible.

I'm not surprised that 80m on the endfed is a bit better than the 40m
dipole. But what's 40m like on the endfed? That's when the feed impedance
(and coax SWR) will be very high, and where the RG-213 might perform
better noticeably better than the RG-58.

As I think I said before, although I am an advocate of simply using coax
(regardless), after all these years I am considering in investing in
something like a SG230 remote tuner for the far end of the coax.
--
Ian



adding a suitably cut wire counterpoise at +% for each band should
certainly assist things .