Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old February 18th 06, 05:35 AM posted to rec.radio.amateur.antenna
KG0WX
 
Posts: n/a
Default What the?

OK - I just bought a new in the box 1955 Heath GD-1B grid dipper
with the extra low band coil set. $25. The dipper works FB and I
used an old SO-239 chassis jack plus a bit of 22g wire and a cut
down pill bottle to make a 4t coupling loop big enough to "dip" -
that is I inserted the dipper's coil inside the pill bottle coil
attached
to my feedline.

Now here is where I make myself look stupid - My antenna's best
SWR is at 7185 with a 1.1:1 but the dipper showed max dip at
6990 (I tuned into the dipper with my K2). What's going on here?

Someone educate me.....lol

73's de Ken KG0WX

  #2   Report Post  
Old February 18th 06, 02:23 PM posted to rec.radio.amateur.antenna
Amos Keag
 
Posts: n/a
Default What the?

Resonance and VSWR are NOT related!

My 75 meter mobile antenna is resonant at 3.94 MHz. My VSWR is 5:1.

You are measuring two different things.

The dipper is a very nice tool. I owned the Heathkit unit in the olden
days. I now use the Military surplus AN/PRM 10.

KG0WX wrote:

OK - I just bought a new in the box 1955 Heath GD-1B grid dipper
with the extra low band coil set. $25. The dipper works FB and I
used an old SO-239 chassis jack plus a bit of 22g wire and a cut
down pill bottle to make a 4t coupling loop big enough to "dip" -
that is I inserted the dipper's coil inside the pill bottle coil
attached
to my feedline.

Now here is where I make myself look stupid - My antenna's best
SWR is at 7185 with a 1.1:1 but the dipper showed max dip at
6990 (I tuned into the dipper with my K2). What's going on here?

Someone educate me.....lol

73's de Ken KG0WX


  #3   Report Post  
Old February 18th 06, 02:29 PM posted to rec.radio.amateur.antenna
Roy Lewallen
 
Posts: n/a
Default What the?

KG0WX wrote:
OK - I just bought a new in the box 1955 Heath GD-1B grid dipper
with the extra low band coil set. $25. The dipper works FB and I
used an old SO-239 chassis jack plus a bit of 22g wire and a cut
down pill bottle to make a 4t coupling loop big enough to "dip" -
that is I inserted the dipper's coil inside the pill bottle coil
attached
to my feedline.

Now here is where I make myself look stupid - My antenna's best
SWR is at 7185 with a 1.1:1 but the dipper showed max dip at
6990 (I tuned into the dipper with my K2). What's going on here?

Someone educate me.....lol

73's de Ken KG0WX


1. Although it's usually close for simple antennas, the point of minimum
SWR isn't necessarily the resonant frequency. The dipper measures resonance.

2. The coupling loop adds inductance to the circuit, lowering its
resonant frequency.

Roy Lewallen, W7EL
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT +1. The time now is 09:58 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017