To make a long story short, I purchased a DE-31 loop for portability
and it came with a 3 conductor mini-jack to "two clips"
(antenna/ground) adapter. The antenna works fine with the minijack /
but not the clips. I tried the clips with my Edek Torus Tuner... the
clips don't seem to work with that either. The clips are making
electrical contact through, though. I tried the clips with two radios
(one radio doesn't have an antenna jack - hence the issue).

Important details:

The DE-31 has a 3 conductor mini-jack and the adapter ends with TWO
clips, one for antenna and one for ground. The radios don't have
"ground" connectors per-se, so I'm not sure the best place to connect
the ground wire and if that's causing an issue.

When I connect either antenna via the minijack, I can tune the antenna
just fine (I hear the "click" around the proper spot and then tune
slowly) and it makes a marked improvement.

When I connect the Torus Tuner via the clip adapter, I can hear the
"click" and fine tune, but it makes very little difference (on the same
frequencies I tested with the minijack). Remember that the Torus Tuner
has a 2 conductor plug and the adapter is 3 conductor - I don't know if
that makes a difference.

When I connect the DE-31 via the clip adapter, I can't hear the "click"
at all. The DE-31 has a pretty long minijacked wire to connect to the
loop. When I use the clip adapter, removing the wire from the loop,
gives the same reception as having the loop attached.

That is, it seems that on the DE-31 at least, when it's connected using
the clip adaptor, it's using the wire as a 'longwire' antenna, but it's
not interacting with the loop at the end of the longwire correctly (and
reception using the wire varies by frequency). Is this an impedence
mismatch? Could this have to do with not connecting the grounding wire?
Any other possibilities How can this be tested (I do have a
multimeter)/ corrected?

This thread has technical data regarding the insides of the DE-31 if it
can be of any help.
I have not moded the unit:
http://www.drmrx.org/forum/showthread.php?t=1210

Thanks for any insights!

Hello,

Can you connect both clips ? one to the antenna and one to a "ground" point ?

It does help to have the ground point...

Charly

The question is, what can I use as a ground point? The seller said the
negative battery terminal... Besides being "sloppy" (maybe put a wire
around the battery door), will that do damage? Any other locations to
ground it, for a portable which doesn't have a ground (or antenna)
terminal?

If I don't use headphones, someone mentioned the headphone jack... Is
that ok? I guess I'd have to buy a minijack... which terminal would be
ground? Do I then not connect anything to the other terminal of the
jack?

Interestingly, at around 15 mHz, using the antenna via the clips, does
seem to work (I can tune the antenna and get sensitivity increase - I
don't know if it 100% matches the jack or not - but it's pretty good).

At around 9 mHz, using the antenna via the clips only seems to see the
wire and not the antenna at the end (tuning does nothing).

Does that show an impedence matching issue?

Thanks

Charly wrote:
Hello,

Can you connect both clips ? one to the antenna and one to a "ground" point ?

It does help to have the ground point...

Charly

a écrit :
The question is, what can I use as a ground point? The seller said the
negative battery terminal... Besides being "sloppy" (maybe put a wire
around the battery door), will that do damage? Any other locations to
ground it, for a portable which doesn't have a ground (or antenna)
terminal?

If I don't use headphones, someone mentioned the headphone jack... Is
that ok? I guess I'd have to buy a minijack... which terminal would be
ground? Do I then not connect anything to the other terminal of the
jack?

Yes it can be ok. I did it. If your radio has a line-out jack, then you can use
it. You can also use the negative connection of the power jack if your radio got
one.


Interestingly, at around 15 mHz, using the antenna via the clips, does
seem to work (I can tune the antenna and get sensitivity increase - I
don't know if it 100% matches the jack or not - but it's pretty good).

At around 9 mHz, using the antenna via the clips only seems to see the
wire and not the antenna at the end (tuning does nothing).


You must tune the antenna VERY SLOWLY ! The KA31 is very difficult to tune
sometime, and you can only see the difference on the S-meter sometime...
Using this antenna without an S-meter is quite difficult, I don't do it.

Does that show an impedence matching issue?

Dunnow... What is your radio ? I did use it with a Sony SW100 and a Sangean ATS909.


Thanks

You're most welcome...

Charly

Is the SW100 antenna jack safe to use with the DE-31 (KA-31) ? The
SW100 powers the antenna which comes with it -- so it outputs voltage
on the antenna jack... When I bought a Torus Tuner (Edek) loop, Ed
especially modified it (and future units) to work with the SW100, after
I requested it.

I actually tried it with the SW100 antenna jack and then reminded
myself that I probably shouldn't. I'm now testing it on the SW100 rod
antenna and the DE1105 rod antenna.
The DE1105 does have an S meter (I don't know what units they use).

My goal is to get the DE1105 with DE-31 to work and then sell my SW100
and Torus Tuner loop. The SW100 and Torus Tuner are both great... but
nowadays, I use shortwave mostly for travel and the SW100 is too
precious and the Torus Tuner is too big to bring along.