Older German dual banana plug connector?

Hello all!

I am looking for a dual banana plug connector to match the socket on a
Leitz microscope from the late 1960s. The individual plugs are somewhere
around 2.5 mm to 3 mm diameter and about 12 mm long. The spacing between
the plugs is about 13 mm. All I need is the plug, not the socket. If a
dual plug is unavailable, I can use two single plugs that fit.

These are used to connect illuminating lamps to a two-output variable
supply (up to 8 V 0.6 A each) in the base of the microscope. Currently,
one output is used for the main illumination, and the other output is
unused. The second output was designed for an optional illuminator for
a scale in the eyepiece, which is probably unobtainium now. Currently
the user is simply shining a flashlight into the window where the
optional illuminator would have gone, but I'd like to create an
"integrated" solution with a small lamp or LED for the scale
illumination.

This connector is exactly the same idea as the 0.75"-spacing dual banana
plug found on much US test equipment, but smaller. Digging around on
conrad.de , I find 2.6 mm diameter single banana plugs. The diameter is
probably right, but the plug seems a little short at maybe 8 mm.
http://www1.conrad.de/scripts/wgate/zcop_b2c/?~template=pcat_area&p_load_area=222110&zhmmh_area_kz=13
Digi-Key carries an EF Johnson part (J457-ND) that is also probably
close, at 2.64 mm diameter, but this one is only 7.4 mm long. Pomona
part number 2244 is almost exactly what I want, but again, the plugs on
this one are only about 7.6 mm long.

Any tips or leads will be appreciated. Thanks!

Matt Roberds

 

[Kevin Cunningham]

<mroberds@worldnet.att.net> wrote in message
news:89Tgf.7092$0h5.4548@dukeread10...

Hello all!

I am looking for a dual banana plug connector to match the socket on a
Leitz microscope from the late 1960s. The individual plugs are somewhere
around 2.5 mm to 3 mm diameter and about 12 mm long. The spacing between
the plugs is about 13 mm. All I need is the plug, not the socket. If a
dual plug is unavailable, I can use two single plugs that fit.

These are used to connect illuminating lamps to a two-output variable
supply (up to 8 V 0.6 A each) in the base of the microscope. Currently,
one output is used for the main illumination, and the other output is
unused. The second output was designed for an optional illuminator for
a scale in the eyepiece, which is probably unobtainium now. Currently
the user is simply shining a flashlight into the window where the
optional illuminator would have gone, but I'd like to create an
"integrated" solution with a small lamp or LED for the scale
illumination.

This connector is exactly the same idea as the 0.75"-spacing dual banana
plug found on much US test equipment, but smaller. Digging around on
conrad.de , I find 2.6 mm diameter single banana plugs. The diameter is
probably right, but the plug seems a little short at maybe 8 mm.
http://www1.conrad.de/scripts/wgate/zcop_b2c/?~template=pcat_area&p_load_area=222110&zhmmh_area_kz=13
Digi-Key carries an EF Johnson part (J457-ND) that is also probably
close, at 2.64 mm diameter, but this one is only 7.4 mm long. Pomona
part number 2244 is almost exactly what I want, but again, the plugs on
this one are only about 7.6 mm long.

Any tips or leads will be appreciated. Thanks!

Matt Roberds

In the past, if I'm remembering right, the big problem was not length, thats

unimportant, but diameter. If your plug is to short, no problem, there's a
lot of contact area and distance. Radio Shack used to have a push plug that
had a huge amount expansion-contaction. It was dirt cheap and easy to get
then expand it and in it would go.

Kevin Cunningham
SMS