I built an IM2420 back in 1983. It had first rate boards and components. Worked perfectly. T'was a thing of beauty. Last I heard it was living in the Kansas City area.
Just picked up a working IM2420 for $8 at the local flea market. Hooked up to my GPS disciplined oscillator. Was off by 34 hertz, after adjustment, reads exactly 10,000,000. Very happy. Whoever built this did a beautiful job, almost looks factory built. Thanks for the video.
Technically, Heathkit has been back for some time and they do have a very limited selection of items, but I doubt they will ever truly be back. The old Heathkit had such a massive range of items. I've built many Heathkits through the years and miss them as well.
I was recently given the 2410. I've got it running with a TCXO synth board in place of the crystal and it's deadly solid now. I'll probably add a GPS 1pps signal to the synth just because I can... ;-) However, I note that mine runs really warm. The 8 LED driver chips are pretty much too hot to touch, as is the big resistor at the back that is wired across the 5 volt regulator. My unit has a 20 ohm resistor there, but the original manual specified a 10 ohm (5 watt). Your video *almost* gave away the value of the resistor in yours, but not quite... I could see two black bands, but the first one was hidden by a wire!! I'm seeing 4.75 volts from the 5 volt supply, which is probably a little below spec, but I don't have any way to confirm. I'm wondering if you notice any excessive heat from yours? And if you happened to see an issue with the value of the 5 watt resistor?
Good afternoon, Jeff I just purchased an IM-2410 needing repair from a local hamfest, and your video gives me a heads-up into the visuals I will find when I open it up. Thanks for the work! Jerry AB3SX
Thanks for the video. Just bought an IM-2410 from eBay in the UK to add to my somewhat meagre Heathkit collection. You're spot on about the reliability and repairability. I really wouldn't buy anything else for personal use at the moment.
I have a SM-2420 I got in a lot of items a while back, it works great what would be the value of it for selling? I would like to know a fair price to list it for sale. Thx
+Randy Metcalf Prices vary depending on where you sell it. The highest prices are generally on eBay. You should be able to get about $50 to $100 for it, maybe at the upper end of this range because it is the factory assembled version.
The 2410 was my first counter and was replaced by the 2420 that's still on my bench today (built in the early 80's). I modified the 2420 by mounting a front panel switch and internal relay to switch between the rear panel 10MHz reference switch since it's a pain to reach behind if I want to engage the Rb standard...still my go-to counter even though I have a Agilent 53131 on the bench as well. 73 - Dino KL0S
Very good information. I have an SM-2420 which looks very much like the IM-2420 you displayed in the video. I don't know what the difference is but probably not much. Mine quit counting so I'll be needing a service manual for it so I'll be surfing the internet for one unless someone has one that reads this?
I built an IM2420 back in 1983. It had first rate boards and components. Worked perfectly. T'was a thing of beauty. Last I heard it was living in the Kansas City area.
So you can connect a signal generator to one of these frequency counters?
Anyone know?
Thank you
Yes. You can connect any signal generator to a frequency counter if you want to measure the output frequency.
@@jefftranter Thank you Jeff. That is exactly what i want to do.
Just picked up a working IM2420 for $8 at the local flea market. Hooked up to my GPS disciplined oscillator. Was off by 34 hertz, after adjustment, reads exactly 10,000,000. Very happy. Whoever built this did a beautiful job, almost looks factory built.
Thanks for the video.
How did you calibrate it? I also just bought one and will need calibration. How can I calibrate it?Thank you.
Wish Heathkit would come back and offer kits again
Technically, Heathkit has been back for some time and they do have a very limited selection of items, but I doubt they will ever truly be back. The old Heathkit had such a massive range of items. I've built many Heathkits through the years and miss them as well.
I was recently given the 2410. I've got it running with a TCXO synth board in place of the crystal and it's deadly solid now. I'll probably add a GPS 1pps signal to the synth just because I can... ;-)
However, I note that mine runs really warm. The 8 LED driver chips are pretty much too hot to touch, as is the big resistor at the back that is wired across the 5 volt regulator. My unit has a 20 ohm resistor there, but the original manual specified a 10 ohm (5 watt). Your video *almost* gave away the value of the resistor in yours, but not quite... I could see two black bands, but the first one was hidden by a wire!! I'm seeing 4.75 volts from the 5 volt supply, which is probably a little below spec, but I don't have any way to confirm.
I'm wondering if you notice any excessive heat from yours? And if you happened to see an issue with the value of the 5 watt resistor?
Mine has a 20 Ohm 2 Watt resistor. The display drivers chips do get quite warm, which is apparently normal.
Good afternoon, Jeff
I just purchased an IM-2410 needing repair from a local hamfest, and your video gives me a heads-up into the visuals I will find when I open it up. Thanks for the work!
Jerry AB3SX
Nice overview of both. I have the IM-2420 which I purchased in the mid-eighties and still use it today for higher frequencies.
Thanks for the video. Just bought an IM-2410 from eBay in the UK to add to my somewhat meagre Heathkit collection. You're spot on about the reliability and repairability. I really wouldn't buy anything else for personal use at the moment.
I have a SM-2420 I got in a lot of items a while back, it works great what would be the value of it for selling? I would like to know a fair price to list it for sale. Thx
+Randy Metcalf Prices vary depending on where you sell it. The highest prices are generally on eBay. You should be able to get about $50 to $100 for it, maybe at the upper end of this range because it is the factory assembled version.
The 2410 was my first counter and was replaced by the 2420 that's still on my bench today (built in the early 80's). I modified the 2420 by mounting a front panel switch and internal relay to switch between the rear panel 10MHz reference switch since it's a pain to reach behind if I want to engage the Rb standard...still my go-to counter even though I have a Agilent 53131 on the bench as well. 73 - Dino KL0S
Great Video! Thank You!
I Owned a IM-2410 Frequency Counter,,Used it for 16 Years with no problems what so ever,,When I Ran A Audio/VCR Repair Shop
Very good information. I have an SM-2420 which looks very much like the IM-2420 you displayed in the video. I don't know what the difference is but probably not much.
Mine quit counting so I'll be needing a service manual for it so I'll be surfing the internet for one unless someone has one that reads this?
Carl Stewart The SM-2420 would be the factory assembled version, and should be almost the same if not identical to the IM-2420 as far as circuitry.