Re: Heathkit Darkroom timer revealed glory!
Randy, you always have cool stuff to post. This is the schematic. The tube (0A2) is a voltage regulator to ensure consistent times. There is a single silicone component (SCR, the black device that looks like a transistor). I repaired an OMEGA timer that was all analog, like this unit, and the only bad component was the SCR.
http://img.photobucket.com/albums/v6...rSchematic.jpg
Re: Heathkit Darkroom timer revealed glory!
When I was younger, I could not afford the fancy Heathkit timer, so I made mine from RadioShack parts using an article in Popular Electronics. Mine used the digital 555 timer chip that had just come out and a 'modern' TO-220 type voltage regulator.
http://img.photobucket.com/albums/v6...acer/timer.jpg
Re: Heathkit Darkroom timer revealed glory!
Quote:
Originally Posted by
ic-racer
Randy, you always have cool stuff to post. This is the schematic. The tube (
0A2) is a voltage regulator to ensure consistent times. There is a single silicone component (SCR, the black device that looks like a transistor). I repaired an OMEGA timer that was all analog, like this unit, and the only bad component was the SCR.
http://img.photobucket.com/albums/v6...rSchematic.jpg
Thanks!
And double thanks for the schematic!
Re: Heathkit Darkroom timer revealed glory!
That Heathkit is a really clean build--beautiful work. You lucked out with the quality. I recently built a headphone amplifier kit and really enjoyed the process. I'll be starting a second "kit" soon--more like a bag o' parts, so I'll have to do some homework to test the circuit voltages.
http://i.imgur.com/BXUQfQj.jpg
http://i.imgur.com/hzpcHHL.jpg
Re: Heathkit Darkroom timer revealed glory!
Yes the audio guys still want TUBES!
Great project Barry.
Re: Heathkit Darkroom timer revealed glory!
Thanks Randy. Yes, tubes are very big in the enthusiast audio world. You wouldn't believe the prices of some of the NOS tubes--they're insane.
Quote:
Originally Posted by
Randy Moe
Yes the audio guys still want TUBES!
Great project Barry.
Re: Heathkit Darkroom timer revealed glory!
Quote:
Originally Posted by
BarryS
... I recently built a headphone amplifier kit and really enjoyed the process...
___
Barry... You did a very nice job with your Bottlehead Crack OTL Headhone Amplifier Kit.
Congratulations!
Are you perhaps thinking... Of doing the 'Speedball' Upgrade? (*You really should)... :)
--
Best regards,
Tim.
_________
Re: Heathkit Darkroom timer revealed glory!
Quote:
Originally Posted by
ic-racer
so I made mine from RadioShack parts
Nice. Too bad RS is mostly cell phones and cheap junk these days. And in bankruptcy too. No surprise.
Re: Heathkit Darkroom timer revealed glory!
Quote:
Originally Posted by
BarryS
Thanks Randy. Yes, tubes are very big in the enthusiast audio world. You wouldn't believe the prices of some of the NOS tubes--they're insane.
You should see the prices for tube type guitar amps.
Re: Heathkit Darkroom timer revealed glory!
I have a high end audio store near me. I checked out their low end $2000 tube system, all hooked up and playing my type of music, not rock and roll. Very nice, but I won't spend that much on audio.
My hearing is not that good, sure I can discern differences, but I am more visually aligned than auditory. Tinnitus requires masking sounds.
My 20 year old Aiwa system is good enough for my space, it never is off.