Debouncing a Vibroplex Bug

In this video we look at the contact bouncing that occurs during the DIT closure on a Vibroplex bug and describe how that might affect your radio. We demonstrate a simple solution for dealing with the "bounce".
As far as capacitor values you could try; it depends... Try whatever you have in your junk box between 200 nf and 900 nf and see what works. It's going to depend on how badly your bug contacts bounce, the voltage and resistance on your keying line and how sensitive your radio is to relay chatter (my Ten-Tec Eagle has an extremely fast QSK relay so it's especially susceptible).
There's likely some kindly electronics engineer that can tell me the equation to use based on the keying line voltage and capacitance of included cabling, but I'm not that smart.

[@PhillytoBayArea]

My grandfather invented the Lightning Bug. I am curious to hear from enthusiast what influence this key had on communication.

[@MidlifeRenaissanceMan]

I picked up a Vibroplex Lightning built in 1936. It’s way too fast for my slow brain, but it’s way cool, and I love that I have the original box even though the leather handle broke decades ago

[@HogRebel]

@@MidlifeRenaissanceManThat’s cool! Don’t think I could handle a bug!

[@KX4UL]

Very good information. Thanks for posting. It's really nice to see you back on KZbin. 73 my friend!

[@kareneighth6045]

Thanks for the visual explanation!

[@HamRadioQRP]

Glad it was helpful!

[@bashcoder]

Nice to see you back in KZbin land 👍

[@HamRadioQRP]

Thanks. This year has presented some personal challenges that have limited my time for ham radio. Hopefully, I'll be able to gradually resume learning and sharing.

[@fourfortyroadrunner6701]

Actually you stated this incorrectly. The cap does not drain at the opening, it charges. Had my first bug in about 1967 as a new general. I was licensed in about 65, I'm 73. I was not licensed continuously, mine elapsed while I was in the Navy, 68--74. NAS Miramar, 70-74, ETR-2, I fixed GCA RADAR and TACAN

[@kurtkikendall3500]

Nice job!

[@HamRadioQRP]

Thanks for the visit Kurt

[@radiorelayinternational4687]

The first step, before modifying the bug, is to make sure the bug is adjusted properly and manipulated correctly. Proper adjustment and manipulation will cure most problems with "split dots" or other artifacts when transmitting. Proper adjustment and manipulation will also help one develop a good, readable "fist" with proper ratio and spacing. This video may be helpful: kzbin.info/www/bejne/p5bOnqyuaJaIrtk

[@mikeb1043]

Thanks for the post. Presumably when the contacts close the capacitor is discharged instataniously across the contacts. This would mean (depending on the ESR of the capacitor) very high currents would flow, which could cause pitting of the contacts. I would think a small value resistor would be needed in series with the capacitor to limit the current. Mike

[@HamRadioQRP]

Keying circuits on newer transceivers are limited to maximum key voltage of generally under 20 volts DC and less than 50 mA of current. I guess I could do the math but I wouldn't expect high currents to exist. I would think it would be far less than when I use the bug normally with my older tube transmitters. In that case I'd remove the cap... Or maybe leave it in place and see if I have a spark gap generator in low light.

[@Py4tw_radioamadorismo]

Ao invés de um RC, a utilizaçãp de um micro relé melhora muito o problema e sem causar deformação

[@PY2FRQ]

Very good. 73 de PY2FRQ

[@movecizetodobryfilm]

How much nF cap?

[@jameslouis2240]

What value range?

[@HamRadioQRP]

It depends... Try whatever you have in your junk box between 200 nf and 1k nf and see what works. It's going to depend on how badly your bug contacts bounce, how much voltage is on your keying line and how sensitive your radio is to relay chatter (my Ten-Tec Eagle has an extremely fast QSK relay so it's especially susceptible). I'm using a capacitor out of my junk box that works well with my Eagle but is too much capacitance for my C21.

[@smiffykuk]

Good info.. thank you. so why don’t the manufactures mention it. Its terrible to hear some of these keys in action. Why anyone would want to sound like it is beyond me🥴

[@HamRadioQRP]

It depends on the transceiver it's used with. Some rigs buffer the input for you and sometimes it depends on the method you are using to input the key. For instance; my Ten-Tec Eagle buffers the input if I route the bug into the actual "key" input but swapping from paddles to straight keys on the Eagle's key input is not straightforward (plus it's in a really hard to access place on the back of the radio). So I leave a paddle plugged into the "key" input while I run the bug and other straight keys in parallel into the Eagle's ACC/PTT input. That way I can choose to use either my manual keys or the keyer without switching anything out. The ACC/PTT input on the Eagle is not-buffered. Additionally, the keyer built into the Eagle is Iambic Mode B which I never got used to, so I prefer to use a single lever key with that keyer to avoid mistakes when squeeze keying in mode B. Previously I was routing all my manual keys through an old HamKeyer external device that had an adjustable buffer for debouncing bugs. But in an attempt to simplify the wiring at my desk I removed that rat's nest. I finally tired of the scratchy bug and in the process of trying to find a suitable capacitor in my junkbox to smooth out the bug with the Eagle, I figured I'd make the video.

[@christophermaness415]

@@HamRadioQRP what value of cap?