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Bob is going to send me to the library this week to get this book. I really don't know of any other articles on the design. For years the best info I could find was the Avanti Patent. As far as it working like a non apparent collinear, a half wave over a half wave with the correct phasing section produces 3 dbd. The Sigma or Vector design properly constructed reaches the same 3 dbd. I enjoyed the other threads you mention as well.

Jazz, I've done exactly what you suggested with using 1/4 wave 30 degree upward elements. It does work and it's much easier to get the ideal angle once you remove the loop. Full 1/4 wave elements only work without the loop since the loop adds to the electrical wavelength. I did see gain go up by doing this however, it was not uniform in all directions. The radials without the loop provide less bandwidth and some pattern distortion favoring directions with the 4 radials and producing small nulls in between.

Sirio and my company have entered an agreement where they custom manufacture a few different antenna models to my specifications exclusively for Norwalk Electronics. As such the FM versions of these antennas all get Teflon gamma matches and RF connectors up to 7/16" DIN. Since my antenna is less then 9 feet tall, the tubing is exceptionally rigid. Prior to this I had been constructing them by hand in copper and brass for many years.

Far field testing is easier then you think, you just have to start thinking backwards..... Do it in receive. Don't ask for a signal check on the other end. Antenna gain in RX is the same as gain in TX so long as the matching network can handle the power. With no special equipment you can do this. The hardest thing is finding an appropriate place to tune your antenna. You need to be at least a half wave above ground on this antenna otherwise your VSWR will change when it's installed higher.

Next, get a friend in the distance to use a junk radio to transmit a continuous unmodulated carrier on an unused frequency close to where you talk. Connect the antenna under testing to another radio that has an analog signal meter on it. You can use speaker wire soldered to the back of the radios meter and extend the wire out to feed a digital volt meter set on the 200 mv DC scale. Now you have a stable signal to reference against and an accurate way to measure any change. Just keep the RF gain down so that your readings are taking place some where close to half scale on the analog meter or receiver AGC may start to throw you off.

<blockquote data-quote="Shockwave" data-source="post: 155977" data-attributes="member: 10882">Bob is going to send me to the library this week to get this book. I really don&#039;t know of any other articles on the design. For years the best info I could find was the Avanti Patent. As far as it working like a non apparent collinear, a half wave over a half wave with the correct phasing section produces 3 dbd. The Sigma or Vector design properly constructed reaches the same 3 dbd. I enjoyed the other threads you mention as well.Jazz, I&#039;ve done exactly what you suggested with using 1/4 wave 30 degree upward elements. It does work and it&#039;s much easier to get the ideal angle once you remove the loop. Full 1/4 wave elements only work without the loop since the loop adds to the electrical wavelength. I did see gain go up by doing this however, it was not uniform in all directions. The radials without the loop provide less bandwidth and some pattern distortion favoring directions with the 4 radials and producing small nulls in between.Sirio and my company have entered an agreement where they custom manufacture a few different antenna models to my specifications exclusively for Norwalk Electronics. As such the FM versions of these antennas all get Teflon gamma matches and RF connectors up to 7/16&quot; DIN. Since my antenna is less then 9 feet tall, the tubing is exceptionally rigid. Prior to this I had been constructing them by hand in copper and brass for many years.Far field testing is easier then you think, you just have to start thinking backwards..... Do it in receive. Don&#039;t ask for a signal check on the other end. Antenna gain in RX is the same as gain in TX so long as the matching network can handle the power. With no special equipment you can do this. The hardest thing is finding an appropriate place to tune your antenna. You need to be at least a half wave above ground on this antenna otherwise your VSWR will change when it&#039;s installed higher. Next, get a friend in the distance to use a junk radio to transmit a continuous unmodulated carrier on an unused frequency close to where you talk. Connect the antenna under testing to another radio that has an analog signal meter on it. You can use speaker wire soldered to the back of the radios meter and extend the wire out to feed a digital volt meter set on the 200 mv DC scale. Now you have a stable signal to reference against and an accurate way to measure any change. Just keep the RF gain down so that your readings are taking place some where close to half scale on the analog meter or receiver AGC may start to throw you off.</blockquote>

[QUOTE="Shockwave, post: 155977, member: 10882"] Bob is going to send me to the library this week to get this book. I really don't know of any other articles on the design. For years the best info I could find was the Avanti Patent. As far as it working like a non apparent collinear, a half wave over a half wave with the correct phasing section produces 3 dbd. The Sigma or Vector design properly constructed reaches the same 3 dbd. I enjoyed the other threads you mention as well. Jazz, I've done exactly what you suggested with using 1/4 wave 30 degree upward elements. It does work and it's much easier to get the ideal angle once you remove the loop. Full 1/4 wave elements only work without the loop since the loop adds to the electrical wavelength. I did see gain go up by doing this however, it was not uniform in all directions. The radials without the loop provide less bandwidth and some pattern distortion favoring directions with the 4 radials and producing small nulls in between. Sirio and my company have entered an agreement where they custom manufacture a few different antenna models to my specifications exclusively for Norwalk Electronics. As such the FM versions of these antennas all get Teflon gamma matches and RF connectors up to 7/16" DIN. Since my antenna is less then 9 feet tall, the tubing is exceptionally rigid. Prior to this I had been constructing them by hand in copper and brass for many years. Far field testing is easier then you think, you just have to start thinking backwards..... Do it in receive. Don't ask for a signal check on the other end. Antenna gain in RX is the same as gain in TX so long as the matching network can handle the power. With no special equipment you can do this. The hardest thing is finding an appropriate place to tune your antenna. You need to be at least a half wave above ground on this antenna otherwise your VSWR will change when it's installed higher. Next, get a friend in the distance to use a junk radio to transmit a continuous unmodulated carrier on an unused frequency close to where you talk. Connect the antenna under testing to another radio that has an analog signal meter on it. You can use speaker wire soldered to the back of the radios meter and extend the wire out to feed a digital volt meter set on the 200 mv DC scale. Now you have a stable signal to reference against and an accurate way to measure any change. Just keep the RF gain down so that your readings are taking place some where close to half scale on the analog meter or receiver AGC may start to throw you off. [/QUOTE]

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