Mini Mail #1 - Heathkit GC-1000 Most Accurate Clock

I have found that local fluorescent lamps cause all kinds of noise on AM receivers (including short wave). If you have them, turn them off and see if reception is a little cleaner. I get WWV on 10 MHZ really well here in Minnesota a little after sunset. Excellent video btw...👍

Darrell Ashby

Fran - have a look (if you haven't) at the link in John Piontkowski's comment - it gives more info about the smps module mod your clock has - seems like it did not give any problems with extra rf interference - at least not in that clock - and the original 7805 (or whatever) looks to have been far too hot for comfort - your electrolytics nearby might be fried too. The smps module plainly has dodgy joints, as you showed, so perhaps try and get that working first ? There sounds like far too much hum coming from the speaker, so I guess your clock's 5v rail has way to much ripple, as did the clock in the mod link.

Yep. I have several inexpensive wall clocks which reliably sync with the 60 khz WWVB service ne Boulder, Colo.

I think a 7805, along with its 78xx family, is a linear, rather than a switchmode device. Just a niggle :).

I'm enjoying the mystery, Fran.

Hi Fran. I'm enjoying the mystery :)

Fran - found some info on that power supply mod, seems it was pretty common "fix" http://www.nixie.dk/~jthomas/gc1000.html

BiggieJohn

A wave trap on the antenna may also help to remove the noise from the cell tower. Your power lines are probably also helping to bring in noise. Do you need any clamp-on ferrites ? If so, let me know the i'.d.'s. I can send you dozens for free (except postage). Old programmers motto "RTFM". Cheers

Howard Higgins

if anyone can get the GC-1000 clock working right it's Fran. Looking forward to more of your videos. Thanks for sharing Fran.

David Blake

I didn't want to watch the whole video again, but it looks like you almost have it working around the 21 minute mark. I may be wrong but I think I hear short and long beeps from the speaker at a 1 second interval. I don't think I've ever heard WWV on a speaker but I seem to remember that's what the German DCF77 atom clock transmitter sounds like.

Jac Goudsmit

I like the format, I can fit these sized videos in at different times of the day, whereas with the longer videos I have to find time to sit down and watch them. Thumbs up from me!

Nothing close to getting tones with this unit the way it is. Needs the linear regulator replaced and recalibration I think as a minimum.

Fran Blanche

Not so nice - Check the updated edit today!

Fran Blanche

It's a compromise to get the shadow areas of objects to become visible on YouTube.

Fran Blanche

I kept working on the clock into the night after I edited the video last night and when I woke up I decided to do a revised edit with a few additions and uploaded that today.

Fran Blanche

sorry for all the comments. It probably works fine and the signal is stronger at night. You watch the capture led light while listening to the tones though I've never watched it acquire irl, lol, I guess it's like a watched pot. give it overnight with a strong signal. I had to make a magnetic loop listening antenna to reject much of the interference in my place some of it from ungrounded fios equipment. It may be a niche but I would love to see a Fran GC100 clock vid especially because I don't know how to tune mine ;)

Aaron Nadler

PS that heatsink tower use to dissipate a lot of heat from the 5v regulator but yours has been modded with a dc to dc converter, very nice!!

Aaron Nadler

that resistor isn't extra, it is for setup. I repaired and modded the one my brother built. One question I have, other than cool watch setting and showpiece and other than navigation what would one use the freq output or the rs232 for?

Aaron Nadler

25min is a good video length. So you mentioned the clock uses the US "WWV" service? In the UK the MSF time service is on a very low frequency of 60Khz and is broadcast with very high power. It looks like you have another similar service also on 60Khz in the US called WWVB which it would be very unlikely you couldn't receive. You may have better luck with that if the clock supports it. In fact, great video subject for you. Tell us about broadcast time code services and how they work.

Loved the video Fran. Flabbergasted at the amount of work someone put into making the Heathkit clock from a bag of (how many!) parts, wonder how long it took them and who they were? Did they end up in a career in electronics? Such a shame we didn't get a bit of history in the way of a letter from the original owner, maybe they will see the video and get in touch and fill in some back story.

Leigh

This was great! Thanks! Love the shorter format. I think 15-25 min is the sweet spot for me :-) Very interesting!

Roel Binnendijk

P.S. I really loved the video, and I think the shorter length is a wonderful idea! More please!

HarveyB

The Mostek 3870 is a microcontroller, mask programmed with a custom written program. The use of two likely means that either the functionality required couldn't be accomplished in the available ROM space OR that more I/O was needed. (Each chip has 4- 8 bit I/O ports; handy for driving a bunch of LED's or displays.) I used a bunch of them back in the early 1980's for several short run specialty offshore oil instruments that I designed/programmed. (I used the 38P70 variant that would accept an EPROM chip plugged into the top of the CPU. Think of it as a 1980's Arduino! LOL)

HarveyB

This format works for me, and wow, you get better mail than I do!

Your video is over exposed on this and your previous video. The whites are being driven into clip.

I like it! More please. :)

Love this format! Thanks for posting. By the way, you're never going to get WWV reception in Philly during the day. Try again after midnight.

Jac Goudsmit

I like this type of show. We used the Heathkits to train technicians (work study students). Only had one that never worked. An audio generator which had 4 transistors all mixed up. I bought new ones and some day...

Now that's an antenna! Very cool.

Lots of pros and cons, but bite sized is definitely a win!

Jae Lim

Lol - I have some old Radio Shack CB walkie talkies with antennae like that. Getting WWV in that noisy RF environment is going to be tough without a much bigger one though. Love this format, and the addition of something from Heathkit really makes it special. :-)

Fred Patton

I'm sure you're familiar with "RTFM"... I like this show format.

Howard Higgins

I like this. You can do these anytime you feel like it.

William Alsing

I miiiiiiiiss Heathkit!!!!! I wish they'd come back.

Michelle Stoetzel