[Heathkit] Heathkit SB-610, a new twist

[Dick KF4NS]

Here is strange one. I believe most of you are aware of my months of restoring my old HW-100 and the 
SB-610 which involved quite a bit of work, some of which was due to my own messes created by letting the 
DVM probe slip resulting in some serious sparks flying and parts destroyed.

Well, both are finally in real fine shape, better than new, UNTIL THIS NEW TWIST JUST DISCOVERED.

With the tap coming off the 2nd IF plate of the HW100 (10pf + 1ft of RG-62) I connected the cable to the 
SB610 and tuned the HW100 to a S9 signal and adjusted the IN and OUT tuned circuits for the SB610 which 
was now showing a full 1in. vertical display of his signal with about 50% vertical gain. LIFE IS GREAT ! 
or so I thought.

When I disconnected the cable to the SB610, my HW100 dropped to about half the audio level and the 
S-meter froze at S9 for no apparent reason and the CAL signal showed no movement in the S-meter. I 
reconnected the SB610 cable with the 610 powered off. All went back to normal on the HW100.

It seems that the HW100 tap for the 610 must be terminated by 50ohms and a tuned circuit at the IF freq 
of 3395khz. HMMMM, this is definitely a NEW TWIST. If my luck was not bad I would not have any at all.

73, Dick KF4NS
St Petersburg, FL 33714 USA
Keep The Glow!