I am making various test set ups of different style antennas
which l was a whip style antenna I will procede with testing when
the weather gets in the zero area when I do not expect to venture out
much.
This weeks antenna is a whip style antenna which can be used as a
mobile.
The tests that I anticipate doing is some progressive time cycles of
key down tests all the way up to legal max. This weeks antenna
turned out to have a 250 ohm resistive impedance and I was thinking of
using
a commercial style toroid with multiple taps so I can cover a variety
of antennas with different impedances.( Most are well below 250 ohms)
I have no experience with whip style antennas and was wondering if
there
were any precautions that I should take and whether a single toroid
would be O.K. to use. Some of the antennas will be placed on a fold
over tower
and some will be just above ground level where I have a tube inserted
into the ground
where I can put in different antennas that I have made. Testing will
be done
on bands 160 thru 10M during quiet times to minimize interference.
Wire used on antennas is #18 insulated wire of a household type.
Any pointers would be usefull as I have not performed key down tests
before.
I also intend to have a monitoring camera so I don't go thru to many
8877's
Regards
Art

"art" wrote in message
...
I am making various test set ups of different style antennas
which l was a whip style antenna I will procede with testing when
the weather gets in the zero area when I do not expect to venture out
where I can put in different antennas that I have made. Testing will
be done
on bands 160 thru 10M during quiet times to minimize interference.
Wire used on antennas is #18 insulated wire of a household type.
Any pointers would be usefull as I have not performed key down tests
before.

What is the purpose of your 'tests'? That was not made clear in your post.
To just "key-down" using different antennas without a specific purpose makes
it appear that you are testing some sort of impedence-matching device. Don't
forget to Identify yourself with your call sign during the testing.
As for the toroid transformer - multi-tap sounds pretty useful.
I have wound my own toroid transformers, and they worked fine - covered 10m
thru 80meters but I've not used more than 100 watts - I have even used some
of those TV baluns (twin-lead to coax) - and they hold up well at low power.

On 16 Nov, 17:31, "Hal Rosser" wrote:
"art" wrote in message

...

I am making various test set ups of different style antennas
which l was a whip style antenna I will procede with testing when
the weather gets in the zero area when I do not expect to venture out
where I can put in different antennas that I have made. Testing will
be done
on bands 160 thru 10M during quiet times to minimize interference.
Wire used on antennas is #18 insulated wire of a household type.
Any pointers would be usefull as I have not performed key down tests
before.

What is the purpose of your 'tests'? That was not made clear in your post.
To just "key-down" using different antennas without a specific purpose makes
it appear that you are testing some sort of impedence-matching device. Don't
forget to Identify yourself with your call sign during the testing.
As for the toroid transformer - multi-tap sounds pretty useful.
I have wound my own toroid transformers, and they worked fine - covered 10m
thru 80meters but I've not used more than 100 watts - I have even used some
of those TV baluns (twin-lead to coax) - and they hold up well at low power.

I have made some different type of antennas and I want to be sure that
they don't melt.
This apparently is not unusual for DIY antennas. Seems like I remember
that you should use
two toroids for top band but I am not sure why. Don't usually use
bands other than
14M Hz up. Read today that a commercial transmission line that
radiates is now available ( see
Antenna magazine on line that came out today)Not sure where it is used
tho it would be usefull
for the new amateur antenna design which does not require a ground
plane.
Regards
Art

I have made some different type of antennas and I want to be sure that
they don't melt.
This apparently is not unusual for DIY antennas. Seems like I remember
that you should use
two toroids for top band but I am not sure why. Don't usually use
bands other than

That's probably right since the freq is so low.

14M Hz up. Read today that a commercial transmission line that
radiates is now available ( see
Antenna magazine on line that came out today)Not sure where it is used
tho it would be usefull
for the new amateur antenna design which does not require a ground
plane.
Regards
Art

I don't get that magazine, but it sounds like a beverage antenna or some
sort of 'traveling-wave' antenna, but I thought they were for receive-only.

Testing that antennas "don't melt" sounds like you're putting us on, trying
to get a rise from the conservative hams who believe in not using any more
power than is needed for communication. Putting a kilowatt into a mobile
whip antenna may get you heard - but won't make you hear any better. You
could create a lot of QRM with a combo like that. Antennas are our ears to
the world.
Using a whip antenna on a kilowatt rig is analagous to putting on earplugs
and using a bullhorn to converse with someone sitting across the table at
Thanksgiving dinner - and interfering with everyone else's conversations.
But that's my opinion. You can test your antenna with an antenna analyzer
using milliwatts. Throw out those linears!

On 16 Nov, 18:08, "Hal Rosser" wrote:
I have made some different type of antennas and I want to be sure that
they don't melt.
This apparently is not unusual for DIY antennas. Seems like I remember
that you should use
two toroids for top band but I am not sure why. Don't usually use
bands other than

That's probably right since the freq is so low.

14M Hz up. Read today that a commercial transmission line that
radiates is now available ( see
Antenna magazine on line that came out today)Not sure where it is used
tho it would be usefull
for the new amateur antenna design which does not require a ground
plane.
Regards
Art

I don't get that magazine, but it sounds like a beverage antenna or some
sort of 'traveling-wave' antenna, but I thought they were for receive-only.

Testing that antennas "don't melt" sounds like you're putting us on, trying
to get a rise from the conservative hams who believe in not using any more
power than is needed for communication. Putting a kilowatt into a mobile
whip antenna may get you heard - but won't make you hear any better. You
could create a lot of QRM with a combo like that. Antennas are our ears to
the world.
Using a whip antenna on a kilowatt rig is analagous to putting on earplugs
and using a bullhorn to converse with someone sitting across the table at
Thanksgiving dinner - and interfering with everyone else's conversations.
But that's my opinion. You can test your antenna with an antenna analyzer
using milliwatts. Throw out those linears!

Reference to a mobile was to illustrate the size of the antenna only.
As you can imagine squashing a 160M antenna in such a small volume
does suggest difficulties !
Best regards
Art

art wrote:
...
Regards
Art

You are going to need the big toroids for a KW+. 160-10m, as others
have pointed out, has trade-offs when done with a single balun of a
single type.

The 2.25 (B type, I think--greater cross section area) in. O.D. red
material (number not right in front of me) by Amidon has done 1KW 80-10m
for me well in the past--but I concentrate on keeping the SWR low. High
swr will cause noticeable/damaging heating of the core material--if my
experience is any gauge.

For awhile, you could pick up this material on ebay for a song, just did
a quick search and didn't turn up any usable material for your needs ...
might have to order directly from Amidon.

Regards,
JS

On 16 Nov, 19:19, John Smith wrote:
art wrote:
...
Regards
Art

You are going to need the big toroids for a KW+. 160-10m, as others
have pointed out, has trade-offs when done with a single balun of a
single type.

The 2.25 (B type, I think--greater cross section area) in. O.D. red
material (number not right in front of me) by Amidon has done 1KW 80-10m
for me well in the past--but I concentrate on keeping the SWR low. High
swr will cause noticeable/damaging heating of the core material--if my
experience is any gauge.

For awhile, you could pick up this material on ebay for a song, just did
a quick search and didn't turn up any usable material for your needs ...
might have to order directly from Amidon.

Regards,
JS

I think on this one I will put it on the tower with a tuner and give
it a trial run
with 200 watts. I doubt that I can have a long distance QSO but I can
listen around
for a quiet place to do a low power key down. I will place it
horizontal at
the same time to get an idea of pattern before I invest more time on
that one.
Maybe I need to place a large tuner on the tower and be done with it.
Got two more 160 antennas to make before the snow flies
Thanks for the pointers
Art