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

donate to eham
   Home   Help Search  
Pages: Prev 1 [2]   Go Down
  Print  
Author Topic: CQ Wheel  (Read 8858 times)
DL8OV
Member

Posts: 808




Ignore
« Reply #15 on: January 01, 2018, 01:11:58 AM »

If you've ever seen the 'quality' of German TV then you'll know why I've been spending a lot of time in the workshop working on this.  Roll Eyes

Originally I tried a 12cm diameter wheel with segments cut from the outside edge and a microswitch for the contacts, this didn't work too well because of hysteresis in the switch mechanism. Attempt number two is a work in progress using an opto coupler to provide the switching but it doesn't look right.

Does anyone know of a microswitch type device with little or no hysteresis?

Peter DL8OV
Logged
N3QE
Member

Posts: 5214




Ignore
« Reply #16 on: January 02, 2018, 09:49:08 AM »

Originally I tried a 12cm diameter wheel with segments cut from the outside edge and a microswitch for the contacts, this didn't work too well because of hysteresis in the switch mechanism. Attempt number two is a work in progress using an opto coupler to provide the switching but it doesn't look right.

Does anyone know of a microswitch type device with little or no hysteresis?

Are you using a microswitch with a roller on the end?

I think the issue you are finding, is not so much hysteresis (which would affect both on and off transitions equally if you "centered things up"), but is related to the roller being a good chunk of the size of a dit?

Tell me if this makes any sense or not.

There are different microswitches with different types of "followers" on the end. There are ones with a "V" shaped non-roller follower that might be more appropriate than a roller.

An opto coupler could have the same problem if its beam is a size comparable to a dit notch.
Logged
AC7CW
Member

Posts: 1161




Ignore
« Reply #17 on: January 02, 2018, 01:57:43 PM »

Interesting problem... I don't think you are going to get away from hysteresis since it's such a great way to eliminate switch bounce that it's nearly universal.
Logged

Novice 1958, 20WPM Extra now... (and get off my lawn)
N3QE
Member

Posts: 5214




Ignore
« Reply #18 on: January 04, 2018, 07:45:21 AM »

I also have a real Instructograph and have been playing around with my own paper tape loops for CQ'ing. https://www.youtube.com/watch?v=-7J44bDItE4

There was a real magic in the original oiled paper tapes that made them work in the mechanism very nicely.

So far the paper tapes I've created (X-Acto Knives and tape) aren't very durable but a more plasticy material might be the solution.

I'm thinking that I should hit the arts and crafts store and see what kinds of smooth ribbons they have for the artsy types.

The "contact point" on the instructograph is very small and the cam follower time distortion is not at all an issue.

What I love about this is the spring-wound hand-crank and movable pointer for speed!
Logged
AC7CW
Member

Posts: 1161




Ignore
« Reply #19 on: January 04, 2018, 10:52:21 AM »

We used mylar tapes to load programs into mini-computers. Mylar won't self-destruct, not sure how it is to work with when cutting it by hand, we had computer driven punches for that.
Logged

Novice 1958, 20WPM Extra now... (and get off my lawn)
K5SBR
Member

Posts: 9




Ignore
« Reply #20 on: January 04, 2018, 10:28:12 PM »

Don't confuse the CQ wheel with a "Turquoise Tail-ender". The latter was the strip gizmo. The only ones I ever heard/saw sent only the call. The variable speed of stylus drag was the way to make your call unique in a pileup. As I recall, they were even commercially produced for a while.

Most any micro-switch will require a de-bouncing circuit, just as you should use on any bug or straight key tied to a modern rig. Solid-state keying circuits are much, much faster, resulting in clicks, scratches and other trash on the signal.

73 & have fun in the shop,
Ed
K5SBR
Logged
K1ZJH
Member

Posts: 3654




Ignore
« Reply #21 on: January 05, 2018, 07:17:05 AM »

Another technique was to etch the code pattern around the perimeter of a copper clad disk. A contact finger was used to sense the conductive areas to produce the dits or dahs.

Pete
Logged
W9IQ
Member

Posts: 1845




Ignore
« Reply #22 on: January 05, 2018, 07:39:05 AM »

If I were to build a 'modern' version of this, I would use either a slotted or reflective opto-isolator. That would allow a simple disc construction with black marks for the CW message and no debouncing or wear problems associated with a mechanical switch.




- Glenn W9IQ
Logged

- Glenn W9IQ

I never make a mistake. I thought I did once but I was wrong.
K5SBR
Member

Posts: 9




Ignore
« Reply #23 on: January 05, 2018, 07:53:00 AM »

No doubt an optical approach would be superior and MUCH more quiet. Even the best switch makes a lot of mechanical noise. Shades of a Morse Sounder.

An even more modern approach might involve programming a PIC processor? Oh, that's already been done, for less than the price of a good geared motor. What will they think of next?

K5SBR
Logged
K1ZJH
Member

Posts: 3654




Ignore
« Reply #24 on: January 05, 2018, 03:04:26 PM »

Awww heck... find some RTL flip flops, make a BCD generator, get a bunch of germanium diodes and learn Boolean algebra to make a CW message matrix. K1PLP had a design in an early 1970s QST.
Logged
K5LXP
Member

Posts: 5482


WWW

Ignore
« Reply #25 on: January 06, 2018, 05:05:19 AM »

If I were to build a 'modern' version of this, I would use either a slotted or reflective opto-isolator.

Old roller-type computer mice have two of these inside.

Mark K5LXP
Albuquerque, NM

Logged
WA9CFK
Member

Posts: 203




Ignore
« Reply #26 on: January 26, 2018, 09:24:06 PM »

I think my new Transceiver has a record and playback feature built in. Never though much of the idea of machine call my CQ while the sat and waited for it.
Logged
NQ2N
Member

Posts: 150




Ignore
« Reply #27 on: January 27, 2018, 07:18:44 AM »

Not sure if this has any connection to your topic but here is an article about mechanical telegraph wheel invented by Edison that sent at much higher speeds than Morse telegraph operators who sent by hand.
http://edison.rutgers.edu/telegraphy.htm
 I wonder if the the morse code operators of that time who used the straight key looked down on that new technology and called them "no code operators."
Examples of this can be seen in the BBC production of Lark Rise to Candleford.   
Logged
SM0AOM
Member

Posts: 206




Ignore
« Reply #28 on: January 28, 2018, 01:20:40 PM »

"CQ-Wheels" at coast stations were before my time, but I was told that they were not uncommon.
The CQ Wheel mechanism at SAG used punched tape loops that was interchanged with punched traffic lists.When an operator got a call he disconnected the tape reader from the transmitter and keyed it by his bug or hand key. This went away
with computerisation in the 70's. After this all Morse was generated as stored messages from computer interfaces.

I have only seen one proper CQ Wheel used at an amateur station in the flesh. It belonged to the 50's station used by the late SM6JO, and this Wheel used notches in the periphery and a mechanical switch.
It also had a replaceable segment that permitted the transmission of "CQ DX" instead of the plain "CQ".
Logged
Pages: Prev 1 [2]   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!