SWR was not so bad with the new termination load made on the base of wire wound resistors. I tried the antenna directly connected to IC-718. I
was again on the Air. Clean sound was at the 160 and 80- meter
Bands. Contest stations begin
me. My station was
restored. However it
was already 3.00- a.m. I went to sleep.
At the next day I decided change unsymmetrical RF Transformer
that was used at my Beverage Antenna to transformer with insulated windings. At the times when I installed
the Beverage Antenna I had no stuff to make the transformer with
However, at YORK REGION HAMFEST that was at 31- October,
2015, I bought butch of cables with ferrite ring on it.
Seller did not have any information for the
cables and for the rings on it. However it was a good price and
box with the cables jumped to my backpack. At home I found that
lots of the rings had inner diameter in ¼ inch that allows
me make an RF transformer with insulated windings with standard copper
¼ inch tube (because the rings it was possible inserted
on the ¼ inch tube).
the day before evening with Contest I decided make transformer with insulated windings. I expected that the transformer would
provide better matching of the Beverage Antenna with coaxial cable.
As well transformer with insulated windings should decrease
the electrical noise level. Anyway if the transformer would not
good I may use my old transformer made on the base of LDG Symmetrical
Transformer. You may find lots design of such insulated RF transformer
in the Internet.
Figure 1 shows design of the transformer with insulated windings. For the transformer
it was used 10 ferrite rings and two length of copper tube in
¼ inch OD. Photo shows kit for making the transformer. I should say
that at making the transformer I met some unexpected problem.
I had short length (6- cm) of ¼ inch copper tube. I could
insert the rings on the tube. I had another one length of copper
tube (1- meter length) but I cannot insert the rings on it. The
diameter of the tube was a little wide.
Of course it would be possible to decrease the diameter
with Dremel but… I took the ring and
went to Home Depot. It was wonderful for me that among the rolls
of copper tube in ¼ inch OD I may found tubes on which
I may inserted the ferrite ring as well I may found ¼ inch
tube on which I could not inserted the ring. So
I took suitable tube roll with me.
Cable with Ferrite Ring on it
Note: At my job I did measurement the both copper tubes. Tube on which I may
insert the ferrite rings had diameter in 0.248- 0.2495 inch.
Tube on which I could not insert the ferrite rings
had diameter in 0.252- 0.255 inch. All dimensions were in the