WELCOME TO MY RF TRANSFORMERS PAGE(s) AND INDUCTANCE PAGE.
I bought a few of these "ADAPTER HF" boxes at a flea market. I
was told they were used in some cold war government facility.
The little chassis is visible at the top center of the photos. I
took an exacto
knife and carefully cut out all the potting material. The little
transformer is shown in the photos.
The resistor is something I added to test the rf transformer. It
works very well (low swr up to about 30 mhz). It then creeps up
a little bit until about 53 mhz. Then it rises more rapidly.
I think it will be useful for HF bands and 6 meters and should be
good for 100 watts provided the mismatch at the antenna isn't
too great.
I plan to use this transformer on my little hf tgm hybrid mini
quad beam. I can then use the satellite TV 72 ohm coax. An RF
transformer on each end of the coax.
was told they were used in some cold war government facility.
The little chassis is visible at the top center of the photos. I
took an exacto
knife and carefully cut out all the potting material. The little
transformer is shown in the photos.
The resistor is something I added to test the rf transformer. It
works very well (low swr up to about 30 mhz). It then creeps up
a little bit until about 53 mhz. Then it rises more rapidly.
I think it will be useful for HF bands and 6 meters and should be
good for 100 watts provided the mismatch at the antenna isn't
too great.
I plan to use this transformer on my little hf tgm hybrid mini
quad beam. I can then use the satellite TV 72 ohm coax. An RF
transformer on each end of the coax.
Below pictured is the MFJ SWR analyser that I used to test the balun/transformer.
Pictured right is the rf tranformer I
built. It is from an ARRL Handbook
article for a two band inverted L
fed with coax. The handbooks of
the early 90s feature this article.
See the original article in July 91
QST. Unlike the authors
transformer..I added another tap
for experimental purposes.
The torroid core is a T200-2.
I wrapped mine with teflon
plumbers tape first and used a
little red tape to hold it together.
built. It is from an ARRL Handbook
article for a two band inverted L
fed with coax. The handbooks of
the early 90s feature this article.
See the original article in July 91
QST. Unlike the authors
transformer..I added another tap
for experimental purposes.
The torroid core is a T200-2.
I wrapped mine with teflon
plumbers tape first and used a
little red tape to hold it together.
Here is a picture of a prototype model of an remote tuned "r7 style" vertical. These "no radials" verticals all
use a similar system of feed. This picture has the CushCraft "black box". The Cushcraft web site had some
good close up pictures of the BLACK BOX. The EI7BA web site gives details on how you can build one of
your own. I haven't had time to fiddle with my R7 style vertical project lately.
use a similar system of feed. This picture has the CushCraft "black box". The Cushcraft web site had some
good close up pictures of the BLACK BOX. The EI7BA web site gives details on how you can build one of
your own. I haven't had time to fiddle with my R7 style vertical project lately.
I will be adding more very soon to this web page
for now..CLICK HERE to go back to my
antenna ideas page..or (use your browsers
BACK BUTTON) ..CHEERS..ES 73 EARL VE3AB
for now..CLICK HERE to go back to my
antenna ideas page..or (use your browsers
BACK BUTTON) ..CHEERS..ES 73 EARL VE3AB
END OF THIS PAGE.
This Honeytek inductance and capacitance meter is my
newest toy. I bought this on ebay and it was a very
reasonable price of $24.99 or $29.99 (something like
that)! The price and the fact that it measures
inductance up to 20 henries sold me on this meter.
It seems to be reasonably accurate. But I have to verify
this by using some known standard components to
verify this.
Pictured left, is one of many 2.5 millihenry inductors
that I purchased on sale. They are used in audio
circuits. When measured with my new instrument, they
were 2.5 millihenries plus a little bit. So..to me it is a
useful device.
Pictured left is my storage for inductors. I've started
sorting the inductors in my junk box. Between the
"HONEYTEK" METER, my Autek Rf Analyser and the
color codes on the inductors, I can sort the inductors
into values which are reasonably accurate.
The Autek RF analyser seems best for small values of
inductance such as 0.1 microhenry to about 150 uh.
Above 150 uh, the Autek unit does not give a reading
so I have to rely on the honeytek unit.
I have another inductance measuring device, a heath
Q meter. I may use the Heath meter in conjunction with
these other meters. The Heath meter is an old tube
unit but it does have a capability of measuring Q.
Q is the quality of merit of a coil. Coils with very fine
wire often have high resistance which lowers the Q of
the inductor. It is lossy as a result. The type of winding
also factors into the equation.
newest toy. I bought this on ebay and it was a very
reasonable price of $24.99 or $29.99 (something like
that)! The price and the fact that it measures
inductance up to 20 henries sold me on this meter.
It seems to be reasonably accurate. But I have to verify
this by using some known standard components to
verify this.
Pictured left, is one of many 2.5 millihenry inductors
that I purchased on sale. They are used in audio
circuits. When measured with my new instrument, they
were 2.5 millihenries plus a little bit. So..to me it is a
useful device.
Pictured left is my storage for inductors. I've started
sorting the inductors in my junk box. Between the
"HONEYTEK" METER, my Autek Rf Analyser and the
color codes on the inductors, I can sort the inductors
into values which are reasonably accurate.
The Autek RF analyser seems best for small values of
inductance such as 0.1 microhenry to about 150 uh.
Above 150 uh, the Autek unit does not give a reading
so I have to rely on the honeytek unit.
I have another inductance measuring device, a heath
Q meter. I may use the Heath meter in conjunction with
these other meters. The Heath meter is an old tube
unit but it does have a capability of measuring Q.
Q is the quality of merit of a coil. Coils with very fine
wire often have high resistance which lowers the Q of
the inductor. It is lossy as a result. The type of winding
also factors into the equation.
RF TRANSFORMERS and baluns
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