I have constructed a 915 MHz 1/2 wave, end fed antenna that fits onto
the end of a SMA plug based on help from you guys. I have some pics of
the construction if anyone is interested in taking a look.
Where is the appropriate place to post these jpg files ?

I am accessing this newsgroup from my email client presently.

I am not sure how I can optimize this yet. My antenna Analyzer is the
MJF unit that only goes to 440MHz.

I have a 1GHz spec analyzer, 1GHz Sig Gen and a Telonic VSWR kit that
goes to 2.5GHz but I think the drive required to the VSWR "Rho-Tector"
needs to be higher than the 10dBm from the sig gen.

Could I optimize the design with this equipment, or maybe would I be
better to use RSSI levels from a receiver placed say 3m away from
Antenna under test ?

If the antenna works I will be very excited as it is very simple to
construct in around 10 minutes and at a cost of around $3 (no counting
labour).

Thanks for any help.

Jerry Martes wrote:
"Richard Harrison" wrote in message
...

Cecil, W5DXP wrote:
"The 180 deg. phase reversing coil is the tricky part."

For UHF, you might prefer to use a 1/4-wave short-circuited stub in
place of a coil to reverse the phase. My 19th edition of the ARRL
Antenna Book shows such an antenna, "the super J-pole on page 16-25. At
other frequencies, this might be called a "Franklin Antenna". It`s a
1/2-wave in-phase with another 1/2-wave, one mounted directly over the
other.

The super J-pole is designed for 144 MHz, but can be scaled for any
frequency with proper mechanical allowances. Gain is about 6 dB over a
1/4-wave whip.

Best regards, Richard Harrison, KB5WZZI


Richard

I'd have expected the "gain" to be closer to 4 1/2 db over the 1/4 wave
stub over a ground. is it easy to show where i've missed something?

Jerry