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Author Topic: straight key delay  (Read 2443 times)
KE5PYF
Member

Posts: 12




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« on: August 03, 2012, 10:36:45 AM »

First, tnx for all your help. Newbies like me greatly appreciate your willingness to share your knowledge.

After the key is engaged there is normally a   1 second delay before the rig goes into transmit.
This occurs with the tuner in tuned or bypass mode. It seems to be intermittent in nature on all frequencies. Have defaulted all cw settings in quick and initial set mode. Then adjusted each setting associated with cw one at a time. The rig is an IC718, the key is an old speedy model.
I know nothing about the straight key. Could the worn , out of alignment contacts be the cause?  Ok stop laughing.

David
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G4LNA
Member

Posts: 26




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« Reply #1 on: August 03, 2012, 11:14:48 AM »

Hello David, you could try the key without plugging it into the rig, use a multi-meter, most of them have a beeper in continuity mode, put that across the key and see if it works normally. I had a key that did something similar to that, it had dirty contacts, they can be easily cleaned with a bit of paper run between the contacts while lightly pressing the key down.
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PA0BLAH
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Posts: 0




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« Reply #2 on: August 03, 2012, 11:17:33 AM »

Pretty annoying,

Looks like it is your transmitter, not your key. Can be easily checked by using another key OR, just put two wires going to the key in short circuit, OR measure with an analog meter the current of the key in key down. When is closes late you will notice. Also possible to put a LED in series with the key. Must be on immediately with key down.

When you are adjusting: look at VOX delay and anti-trip. and another one I forget the name of. Kind of sensitivity for noise that trips the transmitter in the on state. Those, except VOX delay ought to be out of action, when in the CW mode.

Vox delay is the delay when you fall silent the transmitter is still on. Anti trip is a desensitizer for noise from your receiver in the shack, in order to prevent that receiver noise to trip your transmitter.

Another possibility is that in CW your sidetone oscillator is used to feed the balanced modulator input. And sometimes that oscillator doesn't start immediately , in case of tubes: a soft tube nearly failing.
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VA7CPC
Member

Posts: 2386




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« Reply #3 on: August 05, 2012, 10:59:29 AM »

+1 for "dirty contacts".   Or possibly an intermittent connection to the key, or the plug into the rig.  All easy to check.

As suggested, try pulling a piece of typing paper (oops -- copier paper) through the contacts while gently holding them closed.  Or use a piece of soft cloth with some alcohol on it in the same way.  If it comes out dirty, you've probably found the cure.

            Charles
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K7KBN
Member

Posts: 2802




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« Reply #4 on: August 05, 2012, 05:34:26 PM »

Charles - my wife and I had a "senior moment" at Staples the other day when we referred to "typing paper".  Apparently they didn't have any!

They had about a bajillion cases of 8-1/2x11 copier paper, though.  It works.

When our grandsons watched me typing on an old 50-pound office typewriter when they were quite young, the older one explained to his brother that it was "a keyboard with a built-in printer".  That satisfied him.

Back on topic - the metal on the key plug and/or its jack on the rig may have a little oxidation keeping the circuit from being solidly closed.  Try turning the plug in the jack several times; it usually scrapes off.
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73
Pat K7KBN
CWO4 USNR Ret.
K8AG
Member

Posts: 351




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« Reply #5 on: August 07, 2012, 09:10:32 AM »

Hello David, you could try the key without plugging it into the rig, use a multi-meter, most of them have a beeper in continuity mode, put that across the key and see if it works normally. I had a key that did something similar to that, it had dirty contacts, they can be easily cleaned with a bit of paper run between the contacts while lightly pressing the key down.
I have a Fluke 77 and this may show the delay problem even though it is not there.  Seems there is quite a delay on the 77 between when contact is made and when the beeper sounds.  Can't use it as a CPO.  If your meter has the same delay it may be there even with clean key contacts.

73, JP, K8AG
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G4LNA
Member

Posts: 26




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« Reply #6 on: August 08, 2012, 03:39:32 AM »

I have a Fluke 77 and this may show the delay problem even though it is not there.  Seems there is quite a delay on the 77 between when contact is made and when the beeper sounds.  Can't use it as a CPO.  If your meter has the same delay it may be there even with clean key contacts.

73, JP, K8AG


I must admit I've got a Fluke 179 and it doesn't make a very good CPO, it tends to put in extra dits that are not needed Grin

But I've also got an Iso-Tech IDM91E which makes a perfect CPO, so it seems the cheaper the multimeter the better.
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W5DQ
Member

Posts: 1209


WWW

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« Reply #7 on: August 10, 2012, 09:08:36 AM »

First, tnx for all your help. Newbies like me greatly appreciate your willingness to share your knowledge.

After the key is engaged there is normally a   1 second delay before the rig goes into transmit.
This occurs with the tuner in tuned or bypass mode. It seems to be intermittent in nature on all frequencies. Have defaulted all cw settings in quick and initial set mode. Then adjusted each setting associated with cw one at a time. The rig is an IC718, the key is an old speedy model.
I know nothing about the straight key. Could the worn , out of alignment contacts be the cause?  Ok stop laughing.

David

I know squat about the 718 but I'd bet it has nothing to do with dirty contacts. Some older rigs used the VOX circuitry to engage the PTT to actually key the CW mode. The TS440 does this. If you don't engage the VOX button the CW key line won't key the rig. The VOX Delay caused that same problem for me many times when using my old TS440 years ago. If you have to press VOX to key the rig, I'd vote "Check your VOX delay". I'd suggest you set VOX Delay to zero (0) or minimum, VOX gain to mid-range (thought it probably has little to no affect on CW).

Gene W5DQ
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Gene W5DQ
Ridgecrest, CA - DM15dp
www.radioroom.org
W5DQ
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Posts: 1209


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« Reply #8 on: August 14, 2012, 12:45:40 PM »

So any verdict as to what the problem was?
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Gene W5DQ
Ridgecrest, CA - DM15dp
www.radioroom.org
PA0BLAH
Member

Posts: 0




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« Reply #9 on: August 14, 2012, 01:39:29 PM »

So any verdict as to what the problem was?
Was also my feeling, Gene, formulated  in the second reply.

Instead of jiggling around with digital multimeters he could easily put a LED is series with the key, in order to decide wether the key of the transmitter is guilty. But he is impatient and asked the same question more detailed in Elmers.

Bob
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