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Hy-Gain balun coax connector

Nov 10th 2014, 20:22

OA4SS

Joined: Mar 4th 2003, 15:15
Total Topics: 0
Total Posts: 0
I am trying to restore three Hy-Gain baluns from about 30 years ago. New hardware like this is unavailable here in PerĂº. There is no model number stamped on the cases but they look very much like present day BN-86 models. The problem with all of them has to do with the RF connection of one end of the coil to the base plate of the female coaxial connector that is located at the bottom of the balun. These connectors look like the typical, four mounting hole coaxial connectors that we mounted on chases many years ago. The end of the coil is soldered to an L-shaped heavy duty solder lug. This lug is mounted to one of the base holes in the female connector by a rivet. There is a good DC connection when measured with a VOM, but apparently there is corrosion between the rivet and the female connector hole to which is it inserted. The baluns will not match an rf load for any antenna.

My question has to do with the material that the female connector is made out of. The easiest solution would be to take out the rivet and merely solder the end of the coil to the same base connector hole. However, the fact that Hy-Gain used a rivet for this connection makes me suspect that the material used to make the base for the female coaxial connector is some metal that cannot be soldered. I did use a small magnet to see if it would be attracted to the base of the connector. It is attracted to the rivet but not to the base of the connector.

I saw an article stating that this rivet was what would fail to make a good rf connection with time, especially if one lived in an area with high humidity. Lima is right on the ocean and I have been here now for the past 47 years. The article suggested drilling out the rivet and replacing it with a brass screw, washer and nut. But I would think that this would produce a reaction between the brass and whatever the base of the female coaxial connector might be made up of, especially were it to be aluminum.

I would appreciate any suggestions. Many thanks.
Ed P. Schmidt, SJ OA4SS - W9SI
Nov 11th 2014, 13:44

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

Can you substitute a standard 4 hole jack that you know you can solder? Alternately, remove the connector and see if you can make a good solder joint, then install the connector.

You should be able to differentiate aluminum by weighing it. Aluminum is significantly lighter than materials that can be easily soldered.

Zack W1VT


Nov 11th 2014, 17:07

OA4SS

Joined: Mar 4th 2003, 15:15
Total Topics: 0
Total Posts: 0
thanks, Zack, for your suggestions. I think I will see if I can solder a very light wire to the base without taking it out since that would involve unsoldering the center connector which is working fine just as it is. I have not been able to find the female connectors here in Lima. Ed
Nov 12th 2014, 13:47

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I suggest removing the connector because if it attached to a piece of metal--there may be too much heat sinking to obtain a good solder joint with typical soldering equipment--you may need a gas torch or a very big iron.

Zack W1VT
Nov 12th 2014, 17:19

OA4SS

Joined: Mar 4th 2003, 15:15
Total Topics: 0
Total Posts: 0
Good point, Zach. The base of the connector is inserted in a plastic slot. I have a Weller soldering gun with two positions. Several weeks ago we repaired one of these and at least it looked like we got a good solder connection but when one is not sure of the metal to which one is soldering, looks can be deceiving. Later today a good friend of mine will be here to give me a hand: arthritis is not friendly to soldering guns! Ed

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