How many appliance operators does it take to plug in a telegraph key?

[k4kyv]

How to Wire a Straight Key?

[W2VW]

Ham radio is on the job training these days. We need numbers otherwise the whole thing will be given away to fill some budget gap. That's just the way it is.

[Ed W1XAW]

I suppose the brighter side of the story is that many of these guys have no place to go but up!  At least the guy wants to try something that takes some skill to learn.  Knowledge tends to accumulate over time if you keep at it.  In the end the guy is going to be just a little less numb and he's not wasting his life watching TV (or friggin around on the intenet!) if he's trying to learn CW.

Ed

[K1JJ]

Ya know, I really feel for these poor bastards who have never really learned basic electricty theory and try to play the ham game. It must be frustrating as hell.

I mean, most of us here have paid our dues and cracked the books at one time or another and we STILL struggle to keep our rigs on the air...

Can you imagine erasing what you've learned, starting over but having your present shack to maintain ?

T

[W2VW]

How hard can it be to leard how to run a bulldozer?

[John Holotko]

Well, I studied and understand all the theory and stuff but I never dug this concept of "plugging the radio in??". What do they mean by this ?? What is the proper way to plug in the ac power ?

[AJ1G]

On my old Brit tank set Wireless Set No. 19, key polarity would'nt matter.  I found this out the hard way when I first got it going, strapped the Brit No. 7 knee key to my bare leg (wearing shorts on a humid summer morning).  Plugged the key in and got a nasty jolt!  Sdhematic showed that the key was in fact series keying low level B plus, 275V!!! Explains why the J-37 inside the knee key metal enclosure was insulated for both sides of the circuit.  But leakage currents in the humid air and sweat did their thing and outflanked the insulation.  What a stupid design!  Installed a little rat shack 12VDC keying relay for safety sake, and no problems since.  Maybe the key circuit designer was a German sabotuer....

[Carl WA1KPD]

I have mixed feelings about this:

As a 14 YO kid first licensed in 67, I remember being very worried about setting up my dipole. Did the inside of the coax go to the antenna leg nearest my transmitter or farthest away?  Go ahead, laugh but if you don’t know and wonder if it is important check every technical book and show me where it tells you it does not matter.

I finally asked a 15 year old Old Timer (he had been a novice for 6 months) who told me not to worry about it.

I have to be honest, I never really thought about it (the key connections). I just plugged em in. But the responses here and at the site bring up some good points that I should have been thinking about.

The guy was smart enough to ask the question. How many unasked questions get reported in the obituaries?

BTW Don you had a nice signal up to CT on 160 the other night

[KB2WIG]

My phone has 4 wires. How do I connect it to my ICOM?? ... .... ..  klc

[wa2zdy]

I remember the the summer day when 13 yr old WN2ZDY reached for both the key and the plate switch on his Globe Scout while paying attention to neither.  I'm not sure whether the frame or lever was at ground as I could very easily have touched either during this incident.  But it was an eye opener.  If I did that at my age today, it would  be a permanent eye closer. 

I learned a tad bit about cathode keying that day. 

My first reaction to seeing that question posted on qrz.com was "what have we come to?"  But thinking about it, as others have said, at least the guy is trying and willing to ask and learn.   That's better than what about half of new licensees are doing - talking on the local repeater or worse, not getting on the air at all.

[W1IA]

My end fed zepp has one wire...how do I hook it up?

a) staple the wire to the coax.

b) locate tig welder, climb tree, weld wire to coax.

c) throw away zepp and buy a G5RV and learn how to connect pl-259


B

[K1JJ]

Yep, the coax to the dipole question...  For several years as a JN, I would always put the inner coax conductor on the leg that was highest. I rationalized that the chassis/ shield is ground and does nothing... the inner conductor is what put the signal out.... 

When I switched to twin lead [connected directly to the 50 ohm unbalanced rig] I would trace out the "hot" lead and make sure it was on the "proper" leg.

Like I said, I feel for these poor bastards who have to go thru the learning curve of endless circles and tears... 

T

[Ed/KB1HYS]

At least there were a few people out there who took the question seriously and the time to answer.   Alot more would just poke fun and laugh... that's no way to elmer is it...  You'll get more operators of higher quality with patient, friendly teaching than any other way. Mentoring I think is the expression...

We all had someone we knew who got us started right?  I'm sure my grandad thought a lot of my questions were dumb, but I never knew it. 

Or maybe he was just trolling....

[k4kyv]

Actually, if a hollow-state transmitter is wired up properly, cathode keying should not be a safety hazard.  The grid leak and bias supply should be returned directly to ground, not to the cathode of the tube.  If the return is to the cathode, you don't really have cathode keying, but series B+ keying, in the negative lead of the power supply.

With proper cathode keying, the open key acts as a cathode resistor of nearly infinite ohms, so the grid should be negatively biased to near the full power supply voltage, thus cutting the tube off since that negative bias is far beyond cutoff.  But if the tube is actually cut to zero plate current, the cathode would be effectively floating, and there would be nothing to maintain the negative grid bias on the tube.  So the charge leaks off until the circuit finally reaches an equilibrium point, where just enough plate current flows to maintain bias on the tube to near cutoff.  You might say the plate current approaches, but never quite reaches, zero.

The jolt you get off the key is not a result of the HV flowing through the tube and through your body, but from the accumulated charge on the capacitors in the keying shaping circuit and the rf bypass capacitor from cathode to ground.  If your skin is dry, the resistance of your fingers to ground is still high enough to cathode bias the tube to near cutoff.  But the initial jolt from the charged capacitor may be enough to break down the skin resistance barrier and allow the tube to continue conducting, with your finger serving as a much lower cathode resistance.

I don't have the schematic in front of  me to see exactly how it works, but the Eico 720 transmitter uses some kind of circuit in combination with cathode keying, involving the clamp tube as I recall, that keeps the voltage across the key low enough to avoid shock, but at key-down, the full cathode current flows through the key contacts.

One problem I have noted with that circuit is that my solid  state electronic keying circuit, using a TV sweep transistor in a switching circuit, does not allow full plate current.  With that transmitter, the power is reduced to about 60% normal using the keying transistor, but with both homebrew rigs, using classic cathode keying, I get full plate current (about 40 m.a.) in the keyed stage, through the transistor. 

Even the Gates BC1-T reaches full plate current with the transistor.  I cathode key both 807 drivers plus the 2nd 12BY7 buffer stage, and the total cathode current of all three tubes is about 225 m.a. I cannot tell the difference between shorting the keying line directly to ground and key-down using the switching transistor.  Naturally, to save my key contacts, I never attempt to key any of my transmitters directly with my bug, and this would no doubt completely wipe out an electronic keyer designed for use with a modern solid state rig.

But regardless, if I ever key by using a straight key inserted directly into the cathode  circuit, I carefully avoid coming in contact with the hot side of the keying line.  Those capacitors can store up a nasty charge!

Also, with a solid state appliance rig, wiring up the key backwards (with the frame of the key connected to the "hot" lead) is asking for flaky operation due to rf getting into the internal solid state keying circuit.

[W1GFH]

Yep, the coax to the dipole question...  For several years as a JN, I would always put the inner coax conductor on the leg that was highest. I rationalized that the chassis/ shield is ground and does nothing... the inner conductor is what put the signal out.... 

When I switched to twin lead [connected directly to the 50 ohm unbalanced rig] I would trace out the "hot" lead and make sure it was on the "proper" leg.

I recall having the same issues as a JN. I did on the air tests to see if it made any difference which conductor was attached to what leg. It didn't. It taught me how RF radiates in a dipole - much better than any textbook could. (climbs on soapbox) This is exactly the kind of 'learning by experimentation' that ham radio should be all about.

[Glenn NY4NC]

What about the poor guy with the Gotham Vertical? 

Notice the mention of AM in the text.. 

[WA1GFZ]

The Gotham worked quite well on 20 meters...as a vertical