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eHam Forums => Boat Anchors => Topic started by: W5CPT on March 03, 2019, 11:14:23 AM



Title: Heathkit Test Equipment Connectors?
Post by: W5CPT on March 03, 2019, 11:14:23 AM
I inherited two pieces of Heathkit test equipment. They both have an odd (at least to me) output connectors. A bit over a half inch across with a center contact in a piece of Bakelite. Is there a source for these connectors, or perhaps an adapter to BNC or something a bit more common?


Title: RE: Heathkit Test Equipment Connectors?
Post by: KS2G on March 03, 2019, 12:51:39 PM
It sounds like you need one of these:

http://www.switchcraft.com/ProductSummary.aspx?Parent=810

Lots of them on eBay.



Title: RE: Heathkit Test Equipment Connectors?
Post by: K9YLI on March 04, 2019, 07:45:09 AM
 Yup..  plain old   microphone  connectors.


Title: RE: Heathkit Test Equipment Connectors?
Post by: K4CCW on March 04, 2019, 11:34:08 AM
Or, you could use one of these. One of the guys on our antique radio forum makes them and does a quality job. I bought a couple awhile back and was very pleased.

https://www.ebay.com/itm/Heathkit-EICO-Microphone-to-BNC-Adapter/183677300880?hash=item2ac4053090:g:miwAAOSwG-1WxF87 (https://www.ebay.com/itm/Heathkit-EICO-Microphone-to-BNC-Adapter/183677300880?hash=item2ac4053090:g:miwAAOSwG-1WxF87)

They are handy for my work on vintage test equipment and other gear when I don’t want to change out the connectors to BNC permanently.


Title: RE: Heathkit Test Equipment Connectors?
Post by: W5CPT on March 04, 2019, 11:57:36 AM
Or, you could use one of these. One of the guys on our antique radio forum makes them and does a quality job. I bought a couple awhile back and was very pleased.

https://www.ebay.com/itm/Heathkit-EICO-Microphone-to-BNC-Adapter/183677300880?hash=item2ac4053090:g:miwAAOSwG-1WxF87 (https://www.ebay.com/itm/Heathkit-EICO-Microphone-to-BNC-Adapter/183677300880?hash=item2ac4053090:g:miwAAOSwG-1WxF87)

They are handy for my work on vintage test equipment and other gear when I don’t want to change out the connectors to BNC permanently.

Perfect! That is what I really was hoping I would find.
Thanks CCW


Title: RE: Heathkit Test Equipment Connectors?
Post by: KD0REQ on March 04, 2019, 01:03:48 PM
Amphenol MC1M connector, still availiable, try Newark or Allied.


Title: RE: Heathkit Test Equipment Connectors?
Post by: N4NYY on March 04, 2019, 02:09:53 PM
I inherited two pieces of Heathkit test equipment. They both have an odd (at least to me) output connectors. A bit over a half inch across with a center contact in a piece of Bakelite. Is there a source for these connectors, or perhaps an adapter to BNC or something a bit more common?

I have restored about 3 pieces of Heathkit test equipment, and have changed all to BNC. With BNC, you can use BNC adapters to just about anything. Those Heathkit connectors were useless.

Unless your objective is a museum piece or eye candy for the shelf and want to maintain originality, I would suggest changing it over to BNC.


Title: RE: Heathkit Test Equipment Connectors?
Post by: WA4JQS on March 04, 2019, 07:09:55 PM
I have a few doz of them in the shop.

73 Tony WA4JQS


Title: RE: Heathkit Test Equipment Connectors?
Post by: G3RZP on March 06, 2019, 01:39:04 AM
A cheap and cheerful hermaphroditic connector. But screw on connectors can be a real pain on test gear.


Title: RE: Heathkit Test Equipment Connectors?
Post by: VK6HP on March 06, 2019, 02:58:23 AM
I found a cache of the Switchcraft brand at one of the local music shops.  Popular with vintage electric guitar folks, apparently.


Title: RE: Heathkit Test Equipment Connectors?
Post by: KI4VEO on March 07, 2019, 12:52:45 PM
I some a few of those microphone connectors on my Heathkit equipment.  Replaced them with BNC panel mount connectors with some thin flat washers underneath them, as a shim.

https://www.alliedelec.com/product/amphenol-rf/031-2221/70142615/?&mkwid=sqEilXhLo&pcrid=334950710599&pkw=&pmt=&gclid=EAIaIQobChMI_9qy-PLw4AIVwR6GCh2EWwPVEAYYBiABEgLLs_D_BwE&gclsrc=aw.ds


Title: RE: Heathkit Test Equipment Connectors?
Post by: W9GB on March 08, 2019, 11:26:04 AM
Quote from: W5CPT
They both have an odd (at least to me) output connectors.
A bit over a half inch across with a center contact in a piece of Bakelite.
Heathkit used a Very COMMON connector found with Public Address (PA) systems
 and microphones since 1940s/post-WW2.
Still Popular with Musicians, like Blues Harmonica players, using 1950s Hi-Z microphones
that have that connector type.  70+ years later, Switchcraft is still manufacturing these.


Switchcraft Vintage Microphone Connector, 2501F
http://www.switchcraft.com/ProductSummary.aspx?Parent=810

These connectors have 5/8-27 threads designed for use with single conductor
microphone cable with 0.281 inch (7.14 mm) maximum outside diameter.

Coupling ring on 2501F is removable for fast change from female to male type.
Spring assembled into body, cable braid and spring clamped by
 hollow set screws .281 inch (7.14 mm) maximum cable diameter.

Switchcraft 2501F connectors : SHOP for BEST Pricing.
AVOID Inferior Asian copies ... demand non-existent outside American designs.

Arrow Electroncs, $6.42
https://www.arrow.com/en/products/2501f/switchcraft
Digi-Key, $6.51
https://www.digikey.com/product-detail/en/switchcraft-inc/2501F/SC1982-ND/1289503
Mouser, $7.31
https://www.mouser.com/ProductDetail/Switchcraft/2501F?qs=zRnNmUVysJewR0Ju%2FRPvfA%3D%3D
Allied Electronics, Guitar/Music Centers, Amazon, Newark also stock this connector.

The Switchcraft 2501MP connector (on Heathkit chassis) mounts in .390 inch (9.92 mm) diameter hole.
The Switchcraft 44 adapts 2501F to fit standard 2-conductor phone jack.
===
SOME Bench Technicians, with a large inventory of test cables, will change this to BNC.
This MOD should be installed to be REVERSIBLE.  
Modern Single Hole BNC Jacks (50 ohm or 75 ohm) mount in a “D-hole” with
dimensions: 0.477” x 0.512”


Title: RE: Heathkit Test Equipment Connectors?
Post by: W9GB on March 08, 2019, 11:51:12 AM
AS Noted, in the Amphenol Datasheet for BNC Single Hole Panel Mounts,
there are BNC Specific Models with SAME Hole used by original Switchcraft 2501MP.

Using these REQUIRE NO HACKING, DRILLING, and REVERSIBLE MOD.
https://www.alliedelec.com/m/d/3966852d62d4c30a66c260681c3742b6.pdf