Hi Brian:
Next time we come up there I will be sure to give you some notice. But
I had already taken a side trip to Don's, K4KYV, to get rid of some stuff. I
was needing to spend some time with the kids there in Searcy.
If you are getting a good match and there is no heating then the energy
from the XMTR must be getting to the antenna. I would worry too much about it
all. But it sounds like you have the same brain disease that I have, CAN'T
STAND TO NOT KNOW WHY. I must have spent weeks studying and experimenting with
this matching stuff and neutralizing circuits, don't even get me started. HIHI
One thing I have found is that the breadboard design is the best for changing
and learning and the shot glass can be used for an insulator or to ease the
frustration, which comes often for me.
While on the subject, I must tell you of an experiment I did some time
back (25 years ago). I put a 6AL5 tube in the top box of a Heath Cantenna and
lit it up with a 6V lantern battery. Using only one diode, I connected the
plate directly to the dummy load and the cathode was by passed to ground with a
.01uf ceramic capacitor and then connected to the little RCA jack on the top
box. Now I had a decent peak reading RF detector. I just measure the DC on
the RCA jack to indicated the peak of the RF voltage (very accurate by the way,
but that's another story). I took 60 ft of open wire balanced line made of
#12 wire with Phenolic spacers about every foot and stretched it out across the
back yard suspended by wood chairs and such. The dummy load RF detector was
then attached to the far end. I had the balanced antenna tuner connected to
the feed end and a SWR meter between the tuner and the XMTR. I adjusted the
tuner so that running 800 watts and with the SWR meter sensit
ivity all the way up it showed nothing on the reflective meter. I then took
my Simpson meter out to the dummy load and measured the voltage at the output
of the 6AL5 RF detector. I of course don't remember the exact voltage but
let's say about 250V DC. Then I connected 100 Ft of RG8 to the dummy load and
the other end to the SWR meter. The SWR meter still show flat but the RF
detector meter showed less voltage, not much less but something like 240V. I
thought maybe I have made a slipup somewhere so I when through all the
procedures again making sure that I disconnected the battery from the 6AL5 when
not measuring so as not to have the filament voltage going down in between
measuring. I got the same results each time. So I was finally convinced that
the losses in a good tuner are negligible and the looses of coax far exceed the
losses of open wire line.
John, WA5BXO
______________________________________________________________
Our Main Website: http://www.amfone.net
AMRadio mailing list
Searchable Archives: http://www.mail-archive.com/[email protected]/
List Rules (must read!): http://w5ami.net/amradiofaq.html
List Home: http://mailman.qth.net/mailman/listinfo/amradio
Post: [email protected]
To unsubscribe, send an email to [email protected] with
the word unsubscribe in the message body.
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
