Topband: Chassis Bonding

[Shoppa, Tim]

K9YC writes:
> There is no problem with V- bonded at load equipment (the rig). The problem is bonding at the power supply, and that is EASY to fix
> -- indeed, many (most?) power supplies are built  either with V- NOT bonded, or with nothing chassis-referenced and a removable jumper
> at the output. All Astron supplied I've looked at are built this way -- indeed, all I've looked at had the bond to the mounting stud of terminal
> strip that was insulated from the chassis by paint. So they were NOT bonded, and neither was the green wire, which went to the same lug.

My observations of Astron ground wiring are similar to yours but I come to a different conclusion.

The V- goes to the terminal strip lug and the terminal strip lug is attached to painted chassis by screw, but I would assume that this makes a poor and intermittent connection between V- and chassis ground.

"Insulated by paint" seems like a very poor idea. It's like someone thought "my boss told me to do this, I don't think I it should be done, and if it isn't worth doing then it isn't worth doing well" :-)

Lifting the ground connection to V- is a very common modification to Astrons and some sources (e.g. http://www.repeater-builder.com/astron/astron-intro-stuff.html ) tell me that Astron has vacillated between grounding V- to cabinet and not grounding and isolating it with 3K ohm resistor over the years.

Tim N3QE