CW7C Keyer

[n8yd]

Hello. I purchased the CW7C Keyer at Hamvention, just a couple of weeks ago. I also had poor luck with the U2-4093 IC. Upon its replacement, I can get a steady stream of Dits or Dahs, however, it's not Dits AND Dahs. There is no difference between the paddles.

Could the problem be another IC?

Thanks!
Adam, N8YD
Ansonia, Ohio

[RDEngineer]

There have been reports of this condition in the past. The fact that changing the 4039 helped is a key. One thing that appears t be happening is there is a race condition with the signals that form the dots and dashes. Try reversing D1 and see is it fixes the problem. Apparently the newer batches of IC's are using newer productions processes and they are faster than in the past. Reversing D1 changes the duty cycle of the oscillator giving a to a longer low to high time ratio.

Of course I must make mention that over 95% of the problems with returned kits are associated with incorrectly installed components. poor solder connections and bridges. In your case this is probably not the problem but It is always good to remind the builder. If this does not correct the problem please give us a call directly and talk to Pat in the tech department. That way you will get a response for sure since we may miss something here on the forum.

[cnk10009]

Assembled my CW7C very carefully, checked, double & triple checked everything.

...has all the syptoms of the other posts.

My 1st Ramsey Kit. ... ._ _..

...must say I'm very surprised it seems to have all the syptoms in previous posts.

Perhaps new parts or kits will be sent out to customers?

Was really looking forward to having a great little keyer.

[RDEngineer]

Sorry to hear that you have the same problem as discussed in other posts. Have you tried the suggestion solution of reversing D1? Unfortunatly we have no way to control the chartersitics of components. There is no way we can predict the parameters of the supplied components. We have identified the problem and supplied a solution here on the forum. We cannot simply send replacement parts to everyone unless it has been determined what the individual problem is. Simply replacing a part with another one, probably from the same production batch, is not a good solution. The CW7 has been around for years and this problem has started to appear in the last year or so. Yes we should possibly provide the suggestion to reverse D1 in the instructions. It takes some time to implement changes to the documents, design, etc. and priorities must be set based on severity and available resources. At this time it is more efficient to address the problem on an individual basis.

Please try reversing D1. If this doesn't solve the problem then contact our tech support directly. The forum is a good way to look for solutions to a problem but is not a good way to contact us since we may not see a post for a while, which adds to your frustration. We can better help you with a direct call to 585-924-4560 or email "techsupport@ramseyelectronics.com".

[cnk10009]

Reversing D1 caused a change...but nothing usable.
No combination of changes to "speed" and "speed range" controls seem to help. At times (perhaps), a dit or dash may emenate at 1WPM...but seems erratic or unpredictable. Perhaps testing each LOT of parts for compatibility before shipping?