Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise

It is currently Jun Thu 27, 2019 5:12 am

All times are UTC [ DST ]

Post New Topic Post Reply  [ 2 posts ] 
Author Message
 Post subject: Shielded Twin Banana to BNC Adapter
PostPosted: Aug Tue 05, 2014 5:44 am 
User avatar

Joined: Jan Thu 24, 2013 4:55 am
Posts: 1312
Location: South New Jersey 08077
I wanted a shielded adapter to accept a 3/4" spaced twin-banana plug and connect to a BNC connector.
The key is a coax UHF-Female to BNC-Male adapter. To this is added a hand-made mounting plate and a grounding banana socket bushing; (solid metal, no insulator at all).
The first photo is the professional GR connector version, but not fully shielded at the binding posts:
File comment: GR adapter
BanannaX2_q1Hw.jpg [ 6.71 KiB | Viewed 1684 times ]

The banana plug fits the center female contact of the UHF connector very nicely.
Here is what I built, with a dual-banana plug shown for scale:
File comment: Assembled Adapter and Plug
BNC-BananaX2_0804142347S.jpg [ 52.1 KiB | Viewed 1684 times ]

In the exploded view it is shown that the mounting plate has a large hole drilled and filed for the UHF connector, and has the grounding banana bushing spaced on 0.75 inch centers, a pair of mounting nuts for the UHF-Female secures the plate. If you don't have a bushing like that in the junkbox, the type of banana socket that used nuts and plastic shoulder washers for insulation could be used without its insulators.
File comment: Exploded view
BNC-BananaExploded-0804142352S.jpg [ 29.98 KiB | Viewed 1684 times ]

Here the banana grounding bushing is seen sideways on the mounting plate (just a small scrap of aluminum sheet).
Detail-0804142354S.jpg [ 29.81 KiB | Viewed 1684 times ]

Ex: Same job, same building, same phone #; 4 Corp's: RCA, GE, Martin, Lockheed-Martin: 48 years

 Post subject: Re: Shielded Twin Banana to BNC Adapter
PostPosted: Aug Tue 05, 2014 1:26 pm 
User avatar

Joined: Feb Sun 02, 2014 9:13 pm
Posts: 1962
Location: Roanoke, VA
The GR adaptor in your first photo (apparently a Type 874-Q2) is designed to mate with a Type 874-ND to provide a well-shielded connection:


Dale H. Cook, Antique Radios / Test Equipment (GR/HP/Tek)

Post New Topic Post Reply  [ 2 posts ]  Moderator: Chuck Schwark

All times are UTC [ DST ]

Who is online

Users browsing this forum: No registered users and 1 guest

Search for:
Jump to:  

Privacy Policy :: Powered by phpBB