tag:blogger.com,1999:blog-4901205574058136834.post2225112252901611887..comments2024-03-26T20:17:30.126-07:00Comments on Every Blade of Grass: Another Three Hour Tour?drjimhttp://www.blogger.com/profile/05647484115197408897noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-4901205574058136834.post-84884798841672491172021-12-12T12:02:03.834-08:002021-12-12T12:02:03.834-08:00I agree 100%! Ceramic, Mylar, Polystyrene, Mica, j...I agree 100%! Ceramic, Mylar, Polystyrene, Mica, just about anything BUT an electrolytic. But, it's audio, and to couple the stages takes more capacitance than RF.<br /><br />The funny thing is that all the voltages are within specs, and the signal flow goes as expected until I get to this one stage, and then POOF! It just goes all wonky.<br /><br />Heath is also running some of the parts AT their ratings. A 15 Volt cap with 15.5 Volts on it? That's just begging for trouble. I'm ordering a bunch of replacement caps today for this unit and the Harmonic Distortion Analyzer I'll be rebuilding. Since they were produced at the same time, I'm expecting that one to be a nightmare, too.drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-69071818794535989642021-12-12T11:27:31.867-08:002021-12-12T11:27:31.867-08:00Using electrolytic caps for coupling was pretty mu...Using electrolytic caps for coupling was pretty much a no-no when I was working at Hughes and Northrop. Even back then they were famously leaky and threw off biases. That may well be your problem with the metering stuff.CapnBobhttps://www.blogger.com/profile/13179687896011182116noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-87389557564270500822021-12-11T17:51:06.009-08:002021-12-11T17:51:06.009-08:00Never worked on any dotmil gear from that era, exc...Never worked on any dotmil gear from that era, except maybe to strip for parts.<br /><br />Heathkits are a dice roll as far as build quality. The SB Series I have were very nicely built, as are the two audio signal generators I have. This one is so-so, and the FM Stereo Multiplex generator was at best a "C-" project by somebody long ago.<br /><br />I'm still spinning my wheels trying to figure out why the metering circuitry won't pass calibration. Some of the power supply voltages are off, so I'm going to replace all the filter caps and all of the electrolytics Heath used for coupling caps in the metering circuitry. The individual stages are DC coupled within the stage, but capacitively coupled between stages. Might have a leaky one in there throwing off the bias voltages.drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-76989129368317620142021-12-11T11:29:03.997-08:002021-12-11T11:29:03.997-08:00Reminds me of my Naval Aviation days fixing old AR...Reminds me of my Naval Aviation days fixing old ARC-27 VHF/UHF transceivers. So much bad workmanship in low-bidder avionics kept us techs in the shop busy.CapnBobhttps://www.blogger.com/profile/13179687896011182116noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-12772921726257492102021-12-10T20:02:05.993-08:002021-12-10T20:02:05.993-08:00Grinding the old stuff out takes some patience, an...Grinding the old stuff out takes some patience, and you can't force the tool. Let it cut at it's own rate, or you WILL snap off the $15 carbide bit.<br /><br />Power tools and SLW don't get along very well.drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-90367450695583992562021-12-10T19:11:08.424-08:002021-12-10T19:11:08.424-08:00Deoxit works! And glad you got the grout done... I...Deoxit works! And glad you got the grout done... I HATE doing that stuff!Old NFOhttps://www.blogger.com/profile/16404197287935017147noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-90351165256165179512021-12-10T14:46:52.759-08:002021-12-10T14:46:52.759-08:00I've also got some in a little squeeze bottle ...I've also got some in a little squeeze bottle with a needle-point applicator. Works great for putting just ONE little drop on accessible switch contacts and pot tracks. drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-27395365471790580302021-12-10T14:09:10.201-08:002021-12-10T14:09:10.201-08:00Deoxit has saved my bacon many times over the last...Deoxit has saved my bacon many times over the last 50 years. Still keep a can on hand. Sure is expensive these days though.FeralFerrethttps://www.blogger.com/profile/18052035175222525103noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-65414561670429112302021-12-10T11:29:56.821-08:002021-12-10T11:29:56.821-08:00It's helped my manual dexterity quite a bit, a...It's helped my manual dexterity quite a bit, and most of my skills at bench work are coming back.drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-4901205574058136834.post-70250880924148432102021-12-10T08:42:28.694-08:002021-12-10T08:42:28.694-08:00Good your fine motor skills still function. Put my...Good your fine motor skills still function. Put my car in the shop this morning for some minor work in years past I would have done. Well Seasoned Foolhttps://www.blogger.com/profile/16670165728759453075noreply@blogger.com