The HD-1410 keyer

One of the items from the most recent electronic assortment purchased on Ebay:

https://wb9kzy.blogspot.com/2026/06/buy-first-think-later.html

was a Heathkit HD-1410 iambic keyer. It's a 5 IC TTL keyer with a discrete transistor clock generator, iambic B and a universal keying output for both cathode and grid block rigs. The design is simpler than the WB4VVF Accu-keyer. The HD-1410 also has an AC supply built in as well as mechanical paddles, a sidetone and a tune switch - it's a pretty complete design.

So I was hoping that it might just work at first try. I was disappointed :( One minor problem was that the included AC cord didn't quite fit right. It will power the unit but if the cord sags or is moved it loses contact. One way around this might be to replace the chassis AC power connector with an IEC "computer" connector ? I'll have to think about it. Similarly the DC power input uses some Molex connector for which I don't have a matching cord. Those aren't huge concerns.

But the real problem was the dits. The dah paddle worked fine but I wasn't getting dits. I took the cover off and started fooling with stuff - I should have thought first and saved time :) First I noticed that the 4 Texas Instruments ICs had tarnished leads so I tried reseating them in their sockets - no help. I also tried a suggestion from the manual and swapped the two 7400 NAND gates on the inputs (IC1 and IC2) but again no help. I found I could get dits if I used a jumper wire between ground and the dit contact. I could also get iambic alternation if I moved the contact spacing black lever to an extreme.

Anyway I noticed something weird. One trick that Bob, W9MO, showed us Novices was to slip some clean paper in between the switch contacts on a key, then close the key and draw out the paper - it sort of burnishes / cleans the contacts. I tried this with the dah without a problem. But then I tried it with the dit and found that the paper moved freely even with the left dit paddle closed. In other words it wasn't making contact. I realized that the left paddle was slightly bent as if someone had squeezed too tightly:

I didn't take a picture so this is from the Ebay listing, the left side is bent

So I bent it back slightly and voila, I had dits ! It was a purely mechanical problem.

Truthfully the paddles aren't super great but overall it's a nice package. One person has even taken out the paddles, repainted their HD-1410 a "Collins" gray (or is that an LMB gray ?):