[heathkit] Low SB-102 amit audio...?????

[Dave <w8qwdave@peoplepc.com>]

Sandy:

Assuming you have checked the tube and it checks good, check the electrolytic caps that are around the tube and the values of the resistances.  My experience has been, and I have worked on lots of 102s and 101s, that considering the age of the rig, many of the values have probably somewhat degraded.  As well check to make sure the component values and the tube, within the balanced modulator are still valid as well.

Just some suggestions.

Dave, W8QW

-----Original Message-----
From: "Alexander N. Gerli Sr."
Sent: Apr 17, 2009 5:03 PM
To: heathkit List Member
Subject: [heathkit] Low SB-102 amit audio...?????

 

 

God Bless You,

 

 

Alexander N. (Sandy) Gerli, Sr.

4012 Bristol Road

Durham, NC  27707-5403

(919) 489-9638

---

From: Alexander N. Gerli Sr. [mailto:ac1y@nc.rr.com]
Sent: Friday, April 17, 2009 5:03 PM
To: 'heath@lists.tempe.gov'
Subject: Low SB-102 amit audio...?????

 

Hi, gang!

 

Well, I’ve got my SB-102 all cleaned up, pots and switches clean and DeOxited and aligned. She puts out full bore just like she should on TUNE.

 

But…..geez, the mic gain stinks. Using my hi-impedance dynamic mic I’ve always used (Turner 33D), the SSB peaks are really poor, like 10-15W on peaks and that’s with a good whistle. Ain’t the mic…that puts out like gangbusters into my SB-101.

 

I note that the series resistor right off the mic plug is a 15K, not a 22K as on the schematic. Obviously, someone changed that out before I got it. My guess is that joe-ham figured that with less series resistance to the V1A grid, he’d get more mic gain, maybe? Anyway, before I go back to a 22K there, what other ideas would bring the mic gain up to where it should be? My tubes all check out on my tester.

 

Rig receives great, great power out. Mic gain is the problem…

 

73,

 

Sandy AC1Y

 

 

Alexander N. (Sandy) Gerli, Sr.

4012 Bristol Road

Durham, NC  27707-5403

(919) 489-9638

 

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