[Hallicrafters] S-36A Question/Observation

[John Schmitz]

I'm in the process of rebuilding an S-36a and have come across an anomaly
that I was hoping one of you guys could shed some light on. This relates to
the RF assy, in particular band switch wafer section SW1e which selects the
osc/mixer injection coils T7 through T9. According to all the schematics I
dug up on the S-36, S36a, S-27, and the RBK they all show a switch wiper
section which is grounded and connects unused T7 and T8 to ground when T9 is
selected. As a matter of fact this is done for all the RF Assy coils with
the exception of T4 through T6 which connects B+ to the unused coils
(essentially the same thing). This makes sense, it results in both sides of
the unused band 1 and 2 coils to be at ground whether it be a hard ground or
an RF ground.

Here's my issue. In my S-36a and in another S-36 (non a) which I looked at,
this grounding wiper is NOT connected to chassis ground, its just left open,
floating, yet all the schematics show it connected to ground. It appears to
have come from the factory ungrounded in both sets I looked at. I'm tempted
to make the ground connection, however, I'm wondering if anyone knows of an
engineering reason why it should NOT be? My first thought is the original
engineers must have left it ungrounded for a reason, but it makes sense to
have it grounded. Was it maybe a production line miss?

Thanks all


John R. Schmitz