Ye canna change the lars o' physics
 

When will these guys learn?

http://cgi.ebay.com/ws/eBayISAPI.dll...tegory=14 956

7dB gain???

I suppose it could be 7dBdummyload, but it's not dBi or dBd which is what
you'd naturally assume..

wrote in message
...
On Wed, 30 Jul 2003 14:12:30 -0500, "Dave VanHorn"
wrote:
When will these guys learn?

The guys selling them, or the guys buying them?

Yes.

I'll make it sound good: 2.2dBi.

A discone is a very fancy, broadbanded quarter wave.

No, I don't. I specifically said I wasn't sure and I had heard - and I
checked commercial sites as well as amateur and this is what I came up with:

The discone antenna is a broadband unity gain (ZERO dB) antenna.

From the commercial sites I checked, it appears that one can expect the SWR
to vary up to 2.5:1 (usually under 2:1), which isn't particularly good at
all.

I was wrong (and did mention I wasn't sure as I haven't used them), but did
bother to check it out. For others, it is always a good idea to verify
information. Zero dB gain (well, one commercial site specified it as zero
dB compared to a dipole or 0 dBd). So, it is better than a dummy load, but
far superior antennas are available with omnidirectional coverage.

73 from Rochester, NY
Jim


"Cool Breeze" spade#abc.com wrote in message
...
jim do you believe everything you read on the internet?

"Jim Hampton" wrote in message
...
Perhaps we should all do a web search on the discone. My understanding
was
(and I am not particularly familiar with the discone, although I have
used
a
biconical - a biconical is to a discone what a dipole is to a
groundplane)
that gain increases with frequency (to a point). It might be possible
(and
I emphasize 'might') to achieve a 7dBi gain (although that sounds high
to
me) in the upper middle frequency range of the device. At 25 to 30 MHz,
it
would likely have a gain equal to or lower than a groundplane. Anyone
care
to do an internet search and see what they can report?

73 from Rochester, NY
Jim

"Dave VanHorn" wrote in message
...
When will these guys learn?




http://cgi.ebay.com/ws/eBayISAPI.dll...tegory=14 956

7dB gain???

I suppose it could be 7dBdummyload, but it's not dBi or dBd which is
what
you'd naturally assume..




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"Jim Hampton" wrote in message
...
No, I don't. I specifically said I wasn't sure and I had heard - and I
checked commercial sites as well as amateur and this is what I came up
with:

The discone antenna is a broadband unity gain (ZERO dB) antenna.

A bit of decent science done:
http://www.antennex.com/shack/Apr03/ontheeh.pdf

I appreciate the URL. I know this thread is getting old, but for what it is
worth, there was a heck of a write-up in an IEEE meeting in 1994 or 1995
concerning Poynting theorem and the fact that antennas can be built that are
very small and have gain. We then had the cross-field antenna and now the
E-H antenna. In theory, this can be done; we are just waiting for a
practical antenna. There are claims; I just wish I could test a couple of
them in an anechoic chamber as well as mounted high against standard
antennas. The cross-field and E-H antennas arguments are starting to become
as heated as the code/no code arguments amongst amateurs (and others).

73 & thanks for the URL from Rochester, NY
Jim


"Dave VanHorn" wrote in message
...

"Jim Hampton" wrote in message
...
No, I don't. I specifically said I wasn't sure and I had heard - and I
checked commercial sites as well as amateur and this is what I came up
with:

The discone antenna is a broadband unity gain (ZERO dB) antenna.

A bit of decent science done:
http://www.antennex.com/shack/Apr03/ontheeh.pdf




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