[Heath] Heathkit SB-610

[Dick KF4NS]

Looking for your input and recollection of what you did. I have now completed a full restoration of my 
SB-610 and have concluded that the one remaining fault, low vertical gain, may  be due to how I have 
connected it to my HW100.

It did work pretty good at one time so now there is a bit of head scratching. I  have no losses in the 
610 and the vertical amp, when driven with a sig gen at 3395khz modulated at 50%, I see .4v (spec. 
recommends .5v input) at the grid and get 23v at the plate. That sounds like the 610 is doing the job. 
The vertical gain pot is fine. So now I suspect it has to be the connection to the rig.

I used RG-174 in the HW100 from the second IF plate and have a 5uuf cap in between. Outside the rig I 
have a short run of RG-58 to the 610. I can only see .1v from the rig. The coax is not faulty nor is the 
capacitor.

What did you use in your Heathkit rig for coax and coupling cap. and what did you feed the 610 with? Did 
you connect to the first or second IF and at the control grid or the plate? I did do a mod to the 100 
which lowers the IF gain to improve gain distribution. This came from my friend Mark's (WB8JKR now SK) 
presentation for optimizing the HW/SB transceivers. When the scope was working fairly good this mod was 
already there. I did realign the rig though at some point since then. The 100 is working great.

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