Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: CW Keying  (Read 5468 times)
WJ0J
Member

Posts: 10




Ignore
« on: October 07, 2012, 05:02:09 PM »


I am starting out in CW. After being able to copy slow CW (5-7 wpm) on the air I decided it was try to send out an CQ. I practiced sending in the "monitor" mode of my ICOM IC-720A and I can clearly hear what I am sending. However, when in the actual CW mode with transmit on, when I key CW I also hear a "revving up" of what I think is the transmitter (fan?) and also the monitor tone. Due to this dual slightly offset sounds I cannot make out the tone of what I am actually sending. This is especially discerning since I am using a straight key and have to now guess how I might sound like on the air. There is no amp, the rig is running barefoot.

The question is: Is this normal? Are you supposed to hear a "fan revving" time you send a dit and a dah?

I am trying to find an elmer to show me how things are supposed to sound like, but until then am wondering if anyone has ideas on what might happening.

Regards,
WJOJ (formerly KB3JAD).
Logged
K7KBN
Member

Posts: 2813




Ignore
« Reply #1 on: October 07, 2012, 05:32:29 PM »

Try using some close-fitting headphones to block out the other noise.

Using a straight key, you should be able to listen to the contacts closing and gauge from that how it sounds.  Granted, you're just getting started, but a correctly-sent letter will sound the same every time and FEEL the same as well.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
WJ0J
Member

Posts: 10




Ignore
« Reply #2 on: October 07, 2012, 06:04:27 PM »


You bring up a good point, I am in fact using well fitting Bose Noise Canceling headphones, so this is not outside noise, it must be in the audio.

Also, as you say, it might just take a little getting used it. Hopefully I can develop a feel soon enough.
Logged
KZ1X
Member

Posts: 3228




Ignore
« Reply #3 on: October 07, 2012, 09:09:33 PM »

Do you have any conventional, that is to say, non-noise-cancelling headphones?

Logged
N3QE
Member

Posts: 2285




Ignore
« Reply #4 on: October 08, 2012, 05:16:57 AM »

Wow, when I started the IC-720A was the new fancy pants radio. Two page playboy style spreads in all the ham magazines. But that was like 30+ years ago.

If you are hearing creaks and groans on the headphone audio on every key-down, it could be power supply drooping, it could be purely an audio artifact, it could be electrical noise from the fan getting into the audio.

It is very unlikely that what you hear in the headphones is what your note on the air actually sounds like. It is just the monitor note plus noise. With a little luck your transmitted note is much clearer. Or if not clearer at least copyable.
Logged
WX7G
Member

Posts: 6131




Ignore
« Reply #5 on: October 08, 2012, 06:37:44 AM »

It could be the noise cancelling headphones. The pair I have produces an audio artifact when I run the amp. To test for this reduce your transmit power as low as it will go and see if the CW sidetone sounds different.
Logged
WJ0J
Member

Posts: 10




Ignore
« Reply #6 on: October 08, 2012, 07:53:11 AM »


Ok, so I tried it with a regular Heil headset, same thing. However, another observation is that the artifact does **not** appear when I do not use any headphone at all, just the icom's internal speakers .... much more tolerable. Even at low power, the artifact is present when using either headphones.

It might be some clicking that is audio output is picking up that the internal speakers are not. Huh.
Logged
K8AXW
Member

Posts: 3900




Ignore
« Reply #7 on: October 08, 2012, 08:48:33 PM »

JOJ:  I can't imagine you being able to hear the fan speed changing while monitoring your sending with noise cancelling headphones or for that matter, any other kind of headphones.

I'm wondering what kind of power supply you're using; is the power supply voltage changing when you key down and or do you have the power supply plugged into an overloaded receptacle?

Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #8 on: October 09, 2012, 04:35:31 AM »

Are you sure you don't have a setting wrong, like perhaps using key sidetone and a monitor function at the same time??

How about QSK or VOX set too fast?

Did you read the manual on using CW with that rig?

 

Logged
PA0BLAH
Member

Posts: 0




Ignore
« Reply #9 on: October 09, 2012, 06:26:49 AM »

When I was a young guy, my mother had one of the first washing (laundry) machines,  I was transmitting, at age 18, the earliest age you could obtain a full license in this country, probably because hams "studying" for years hate to see a kid of 7 yrs old obtaining a full license, and my frequency changed with the mains tension, which changed with the movings of the washing machine. turning left - pause - turning right- pause, and so on,  long enough to remove the shit marks out of everybodies underwear.

But the receivers AR88 R107 T1155 B21 and so on were wide banded, so no problem. I build my own receiver with two huge 77 kHz xtal can filters in a lattice. Couldn't copy phone with that receiver, only CW, that was the reason I persisted to be ham, otherwise I had quit a long time ago. At present I regret this decision. Guys active at that time and still alive, are slaves of the industry, only "operators" not hams because  not able to build anything else as a kit, A kit - beware me - the exercise for a guy of 12 in order to learn basics, and just those guys spit me out.

Sometimes I think: I MUST be stupid because I recognise that stupid people don't recognise they are stupid in my opinion.

So democracy must be demoncracy, because you have to play your theatre and give away sweets to the voters in order to regulate your country the way you think is the best way.

Just a thought

Bob
« Last Edit: October 09, 2012, 06:36:03 AM by PA0BLAH » Logged
WJ0J
Member

Posts: 10




Ignore
« Reply #10 on: October 09, 2012, 09:13:56 PM »

I have a basic jetstream power supply with no voltage indicator so I really cannot tell if the voltage is dropping. The supply is not overloaded, that is for sure since it is the only one plugged into the outlet.

I did read the manual as well as I could. The manual says to depress the transmit switch then key and then put the switch back to receive. No vox. It is a bit of a pain switching between transmit and receive but something I can live with.
Logged
KE4ILG
Member

Posts: 150




Ignore
« Reply #11 on: October 11, 2012, 08:11:49 PM »

I had an Icom 730 which I "assume" is similar to the 720a you have.  I believe I understand exactly what you are experienceing.  There is on the side of the 730 a screw adjustment that I recall was identified as VOX DELAY or something like that.  If you increase the "DELAY" the radio will not revert back to recieve as quickly giving you time to send the next dit or dah.

When I tried to send with the "DELAY" set too short I would hear the receiver kick in and as I hit the key the rig would transition over to transmit which caused the fan to kick on each and every time.  I found this to be very annoying and finnaly got out a small screw driver and adjusted the small screw on the side of the rig. 

These older Icom rigs are not for full breakin and anyone who has operated one will be certain to agree.  So to answer your question it is very normal and easy to fix.  73 Mike KE4ILG
Logged
WJ0J
Member

Posts: 10




Ignore
« Reply #12 on: October 12, 2012, 05:00:09 PM »

Ok .. so I tried that. My rig has both a "VOX DELAY" and a "CW DELAY". There are two ways to operate CW, I could either use the VOX function in which case the rig transmits on key down and after CW DELAY gets the rig back in receive mode. You were right in that setting CW DELAY to a large value prevents the rig from switching back and forth between transmit and receive during a message.

The other way is to use the TRANSMIT/RECEIVE switch right on the rig. Hit switch to TRANSMIT and then rig transmits on key down, after key up the rig remains in transmit mode (does not switch back to receive) but does not send out RF energy, RF is generate only on key down. After message hit the TRANSMIT/RECEIVE to get back to receive mode.

In either of these modes, I still have the original problem. Could it have something to do with a high SWR? I am tuning into a G5RV and best I can do is a 1:2.5. I don't know if this is related but since I started trying CW my MFJ Versa Tuner has start to leak fluid!!! The only thing I can think of is that this mystery fluid is the RadioShack Cleaner and Lubricant spray that I used a while back to lubricate the moving parts and the roller inductor.
Logged
KE4ILG
Member

Posts: 150




Ignore
« Reply #13 on: October 14, 2012, 05:57:16 AM »

Although 1:2.5  is acceptable I am surprised that you are not able to get the SWR lower, depending on where you are operating using a tuner.  With the addition of fluid leaking out of the tuner I am a more than a little concerned.  I would test using low power into a dummy load.  If you are using the tuner dummy load then make the transmissions brief allowing for a cool down time for the dummy load.  

I have a 20+ yr old tuner that I have yet to apply any lubricant to.  I haven't noticed a problem turning the knobs so I have had no reason to.  This makes me wonder if the tuner you have is the problem.  So lets try getting rid of the tuner, no don't thow it out.  I suggest you build a dipole and try it without the tuner and any of the old coax and connectors.  This gives you new start and elimates any outside problems.  

As you can tell its difficult to convey all thoughts via the written word so a local Elmer might be a great help.  You may want to try a local club to see who may be available to come to your shack for a hands on session.  73 Mike KE4ILG

PS The "reving up" of the fan when you hit the key to transmit is what happened everytime I used my Icom 730.  As my friend and Elmer, Jim AF4AT, said the 730 is not a great cw machine.  He also owned one and it did the same thing as mine did.  That is the advantage of having a local Elmer with extensive experience.  I "fixed" it by adjusting the delay and learned to live with the noise.  The most worrysome thing now is the high SWR you have and just some on air experience.  Have fun, Mike.
« Last Edit: October 14, 2012, 06:06:51 AM by KE4ILG » Logged
K7KBN
Member

Posts: 2813




Ignore
« Reply #14 on: October 14, 2012, 09:44:45 PM »

That SWR should read "2.5:1".

As for the tuner leaking, I have a suspicion: water intrusion into the coax and running downhill, as it will (thanks for inventing gravity, Mr. Newton!!  Grin ).  Try disconnecting the coax and see if the connector is wet inside.  Similarly, rotor/rotator cable can serve as a nice water conduit if the high end isn't well-sealed.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!