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-   -   Grid Dip Meters (https://www.radiobanter.com/homebrew/21646-grid-dip-meters.html)

Paul Burridge November 15th 03 06:56 PM

Grid Dip Meters
 

Hi gang,

I've never had a lot of luck with GDMs for some reason. Even with a
decent meter, it seems such a drag tuning across such a vast range
looking for a tiny, easily-missed dip which you have to screw out of
the meter by forcing the sensing coil so far into the circuit
concerned you practically break the circuit board. Am I alone in
finding this potentially invaluable device practically useless in
practice? Is there a more viable alternative?

p.
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill

Dale Parfitt November 15th 03 10:05 PM


"Paul Burridge" wrote in message
...

Hi gang,

I've never had a lot of luck with GDMs for some reason. Even with a
decent meter, it seems such a drag tuning across such a vast range
looking for a tiny, easily-missed dip which you have to screw out of
the meter by forcing the sensing coil so far into the circuit
concerned you practically break the circuit board. Am I alone in
finding this potentially invaluable device practically useless in
practice? Is there a more viable alternative?

p.
--

First rule is to get a good dip meter- the stuff made for the amateur
community is very poor- the Eicos, Heath Millen etc. Pick up a Measurments
model 59. With this meter you can take a 1/2 wave wire- say at 2M and hold
the meter a couple inches from the center and see a huge dip. Other meters
don't even respond when held to the wire. Dips on conventional L-C circuits
can easily be full scale.

Dale W4OP



Dale Parfitt November 15th 03 10:05 PM


"Paul Burridge" wrote in message
...

Hi gang,

I've never had a lot of luck with GDMs for some reason. Even with a
decent meter, it seems such a drag tuning across such a vast range
looking for a tiny, easily-missed dip which you have to screw out of
the meter by forcing the sensing coil so far into the circuit
concerned you practically break the circuit board. Am I alone in
finding this potentially invaluable device practically useless in
practice? Is there a more viable alternative?

p.
--

First rule is to get a good dip meter- the stuff made for the amateur
community is very poor- the Eicos, Heath Millen etc. Pick up a Measurments
model 59. With this meter you can take a 1/2 wave wire- say at 2M and hold
the meter a couple inches from the center and see a huge dip. Other meters
don't even respond when held to the wire. Dips on conventional L-C circuits
can easily be full scale.

Dale W4OP



Uncle Peter November 15th 03 10:06 PM


"Paul Burridge" wrote in message
...

Hi gang,

I've never had a lot of luck with GDMs for some reason. Even with a
decent meter, it seems such a drag tuning across such a vast range
looking for a tiny, easily-missed dip which you have to screw out of
the meter by forcing the sensing coil so far into the circuit
concerned you practically break the circuit board. Am I alone in
finding this potentially invaluable device practically useless in
practice? Is there a more viable alternative?

p.
--


It is kind of hard to get the proper coupling on PCB style coils.
You may have to use a link coupling system (came with some
of the Millens); also solid state circuits can have fairly low Q
circuits, again making it hard to see the dip.

Those were intended for larger tube circuit designs, not PCB
based gear.

Pete



Uncle Peter November 15th 03 10:06 PM


"Paul Burridge" wrote in message
...

Hi gang,

I've never had a lot of luck with GDMs for some reason. Even with a
decent meter, it seems such a drag tuning across such a vast range
looking for a tiny, easily-missed dip which you have to screw out of
the meter by forcing the sensing coil so far into the circuit
concerned you practically break the circuit board. Am I alone in
finding this potentially invaluable device practically useless in
practice? Is there a more viable alternative?

p.
--


It is kind of hard to get the proper coupling on PCB style coils.
You may have to use a link coupling system (came with some
of the Millens); also solid state circuits can have fairly low Q
circuits, again making it hard to see the dip.

Those were intended for larger tube circuit designs, not PCB
based gear.

Pete



Bill Turner November 15th 03 11:23 PM

THERE MUST HAVE BEEN SOMETHING WRONG WITH YOUR MILLEN. BILL T.


Bill Turner November 15th 03 11:23 PM

THERE MUST HAVE BEEN SOMETHING WRONG WITH YOUR MILLEN. BILL T.


J M Noeding November 16th 03 01:40 AM

On Sat, 15 Nov 2003 17:06:34 -0500, " Uncle Peter"
wrote:


It is kind of hard to get the proper coupling on PCB style coils.
You may have to use a link coupling system (came with some
of the Millens); also solid state circuits can have fairly low Q
circuits, again making it hard to see the dip.

Those were intended for larger tube circuit designs, not PCB
based gear.

Item 2.4 described on http://home.online.no/~la8ak/5c.htm
is the solution for dipping pcb coils, and you don't need a
griddipmeter, at all. Another problem with the pcb coil is low
Q-value, and if the coil is loaded too much it won't dip with any
arrangement tried.
also described some GDMs on http://home.online.no/~la8ak/5a.htm -
haven't got the time to re-edit these pages

Jan-Martin
LA8AK
--
remove ,xnd to reply (Spam precaution!)

J M Noeding November 16th 03 01:40 AM

On Sat, 15 Nov 2003 17:06:34 -0500, " Uncle Peter"
wrote:


It is kind of hard to get the proper coupling on PCB style coils.
You may have to use a link coupling system (came with some
of the Millens); also solid state circuits can have fairly low Q
circuits, again making it hard to see the dip.

Those were intended for larger tube circuit designs, not PCB
based gear.

Item 2.4 described on http://home.online.no/~la8ak/5c.htm
is the solution for dipping pcb coils, and you don't need a
griddipmeter, at all. Another problem with the pcb coil is low
Q-value, and if the coil is loaded too much it won't dip with any
arrangement tried.
also described some GDMs on http://home.online.no/~la8ak/5a.htm -
haven't got the time to re-edit these pages

Jan-Martin
LA8AK
--
remove ,xnd to reply (Spam precaution!)

Tracy Fort November 16th 03 01:45 AM

Yep...He probably bought it from you.

Tracy

On Sat, 15 Nov 2003 17:23:50 -0600 (CST), (Bill
Turner) wrote:

THERE MUST HAVE BEEN SOMETHING WRONG WITH YOUR MILLEN. BILL T.




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