The AM Forum

Well, the other day when I should have been at work (but wasn't), the generally inane mid-day 75 meter QSO in which I was involved somehow drifted to the subject of the "kerCHUNK" sound (the sound of big relays kicking in on transmit).

None of the folks' transmitters involved in the QSO produced particularly large amounts of the "sound of power" when going to transmit, even though a considerable amount of power was actually being run at the time (passive voice!) by a number of the participants.

So, a few of us decided to rectify the situation, by

1) configuring a large (but otherwise unnecessary) contactor attached to the side of a rack, and placing a microphone in the general vicinity of the contactor. -and-
2) mixing this extra microphone into the main console to ensure the maximum audio effect.

One of the folks in the QSO simply moved an extra mic near to an already existing contactor, however this also produced some undesirable feedback brought about by modulation transformer talk back.

Someone commented that what we were doing was analogous to "putting potatoes in one's Speedo", and the act was immediately deemed as "adding potatoes" to the transmitter!

I came up with an idea of digitally recording the desired sound, and somehow storing this in a small D/A converter/audio synth IC which could then be configured to produce the desired audio output on demand.

Such a device could allow folks running software defined, modified rice box, quiet class E rigs or just quiet tube rigs (like rangers into linears, etc) to have the illusive "sound of power" - giving them another 20dB of apparent signal strength (like the potatoes in the Speedo!).

This is better than any "roger-beep", and I figure if "they" can do it, why can't we???  This is also done with digital cameras - a fake "click" or "click CLICK" is produced by many digital cameras to give the "feel" of a "real" camera.  Digital Equipment Corporation did this with a small soleniod attached to the VT278 and VT52 terminal keyboards to simulate an IBM Selectric-like feel (the keyboard actually shook a bit when you hit a key - completely fake, since everything was actually electronic and there were no "real" relays involved!).

So, we NEED this !

Currently, my implementation consists of a good microphone next to the side of the rack to which the "effect" contactor is attached.  Upon transmit, the microphone's output is enabled for approximately one second, and is then silenced to avoid unwanted pickup of room effects and other background noise, once the kerCHUNK has completed.  This is very crude indeed, and involves both size (the large rack is needed for a sounding board), the waste of a good microphone (I'm using a 77DX), and of course a lot of other stuff (mixers, etc.) to make it happen.

We need that chip!!!  Put the box in the mic line and you're off!  Any ideas? 

Regards,

Steve

http://www.claysradioshop.com/Toy%20Sounds.htm (http://www.claysradioshop.com/Toy%20Sounds.htm)

Wow. Chips and mixing and extra mics, jeez.  ::) Sounds like taking the really long road to a simple goal. If you replace an existing tx/rx relay with something like a NEMA size 2 motor starter, then it's not really adding potatoes because the new 5lb hammer is actually switching something. ;D Just make sure you go around once and a while and tighten up the cabinet screws.

I like to play around with resisters and caps to get everything to switch sequentially, but only the last click (final) goes out on the air. Maybe we can turn that all around so it all heads out thru the mic... click,click,click,click, BANG. ;D

Derb's got the lowdown right there. We need a nice wolf howl (ahoot, ahoot, ahhhwoooooo) on keyup and about 20 roger beeps on the letgo, lmfao.

On a side note: Just something else useful I've discovered. If you take all the "OO" complaint's and fold them like a little pyramid, then attach them to the walls that way, they make for great sound absorption material to kill room reverb :P



 

There used to be an old timer in 5-land whose homebrew AM transmitter emitted a "Boinnnggg" sound whenever he transmitted.  I think a T/R relay generated an acoustical vibration in his VFO.  It was a one-of-a-kind unique sound never heard on any other station, but he was famous for it.  I think he changed over to slopbucket before he joined the SK list.

How about using a 50 Hz audio generator to introduce a small amount of hum on your signal to give it that exotic 50~ sound like Radio Moscow and some other SWBC stations of the days of yore?  You would have to get rid of every trace of 60hZ hum to make it sound authentic.

it makes me feel ....wierd... to know i heard that Radio Moscow 50 cycle hum for years and never thought a thing of it. It was just there. Me and my wife were talkin about obsolete social references the other day and we realized we (mid/early 40's) were the last group to know what life was like without home computing and the internet. A world were children went OUTSIDE to play.

now they mimic it on their Wii's.

 

Don, was it 50 cyc hum.?   Guess so on a singe phase European standard, but the overtones sounded much higher; You could hear it even on a crappy, tinny 4 tube receiver.  I always assumed it was multi-phased AC, not too well filtered into DC.  At least three phase would yield a 150 cycle underlayment to their sig's. Guess I'll have to research it a bit more.

I was listening to that QSO....

Steve, your extra relay needed some delay between hitting the switch, and the extra relay kicking on......
no "Kerchunck"  came through on your key-up...
Just a pw little "tick"...

----

Kerchunk is the same as when you chamber a round in a pump gun.

Reminds me of those ads you see for the 'Browning Ping' to make your radio sound like the Browning twins. Or maybe those Ferrari kit cars from the 80s?  ;)

Yep, you just lose some of the magic when you move to The Dark Side. Not to mention the fun of having your friends hear, over the air, when your rig craps out.

The most notable kerCHUNK (or, more accurately, *THWACK*) that comes to mind is the W2INR 21E. That thing really smacks the aether everytime he keys it up. You just know there's power behind it.

Brentina's Class E rig, though dark, does emit a nice 'High Tension' sound when he's transmitting. Similiar to that low zzeeeeeeeeeeeeeeeeeeeeeeeeeerrr hum you hear walking past a substation. Always makes me think of the old Sci-Fi movies with Tesla coils, Jacob's Ladder, and those big knife switch panels.

You boys have WAAAAY to much time on yer hands......

Not always  ;)   My old "big" tube rig was amazingly quiet on key up (even though I was switching a 10,000 volt power on and off!).  All of the relays were spring mounted (not screwed directly to the racks) in an effort to reduce background hum (relays usually vibrate a little) and other noises.   Now, another reason for the quiet T/R was to completely eliminate any mechanically transmitted noises which would disturb others in the neighboring room who might be sleeping (when I should be) at 1:00 AM   ;D   I don't have this problem now (room is quite far from the rest of civilization), but at the time, I did - and it would awaken my wife (the "clunking" of the big (very big) contactors).

The result was a fairly quiet transmitter on T/R.

On the other hand, my "heavy metal" class E rig (the one shown in my side picture) makes a lot of noise.  Thing is, I don't use that one most of the time and the others are fairly quiet (as Bruce pointed out).

The other thing I have going on in my shack is the microphone location, type (HIGHLY direction) and usage (I *eat* the microphone)... These combined factors make for a very quiet background, even with my noisy transmitters.  I don't hear a lot of T/R noise in Bill KC2IFR's station either - and I know he uses a similar mic and technique on the air.

Also,  loud relays (loud enough, with enough noise to be BIG on the air) banging over and over on T/R hurt my ears  :-[  (no sympathy here, I'm sure!).  ;D

So, wah wah wah - I want my dewicate widdle ears pwotected, the transmitter to weigh 25 pounds (but put out legal limit!), and I want the sound of a 1930s 50kw rig firing up  8)    Gimm'y the potatoes !!!

Regards,

Steve

  "   
Someone commented that what we were doing was analogous to "putting potatoes in one's Speedo", and the act was immediately deemed as "adding potatoes" to the transmitter!  "

I hope they are placed in the front........................

I determine the sound of power by the position of the S-meter. Tricks are for kids.

I prefer the sound of a good belch thrown in there every now and then. Now THAT is power !

Tell the truth Steve, those relays were quiet as they were suspended with JS clip leads!  ;)

Steve:

My thought was to have a digital chip with the kerCHUNK and another with the sound of a large blower added to your audio.

And I guess you can add some accoustical transformer hum with another digi-chip too!

73,
Dan
w1DAN

YUPPER!! ;D

Ah, yes....the big "kerchunk" and the background buzz/hum.   I had a chance to stand near the power components and contactors of one of the 250kw VOA shortwave transmitters in Bethany, OH, once, during switching.   Mmmmmm,  POWER!!!!!!    ....or the 6 foot tall big iron of the mod transformer on that thing ringing metallically to the audio.....

Those old 50kw RCA and Westinghouse broadcast transmitters were similar in sound, up close.

The old Radio Moscow 50 Hz audio buzz on many of their transmitters in the early 60's is a lost sound now.  I should have made some recordings of them.  I had a 7153 crystal from my novice days and if another station's receiver didn't have a BFO, he still could copy me using the beat from Radio Moscow on 7150.

Oh well, my Viking Valiant still "bongs" when I throw the plate switch......

73
Ted  W8IXY

The Valiant also has a "boinggg" sound on keyup.

edit.  Bah, W8IXY beat me to the punch  ;D

Here ya go Ted!

 Voice of Communizm  (http://amfone.net/index.php?ind=media&op=file_view&iden=155)

 Radio Moscow  (http://amfone.net/index.php?ind=media&op=file_view&iden=48)

Well, some of them WERE suspended using looped clip leads !    We recently had to put up a "happy birthday" sign here at the house for a party, and I used clip leads for THAT, too  ;D   Sherrie was mildly amused  8)

Regards,

Steve

Well, of course! I mean, the S in S-meter means Sound, anyone knows that. The more S it reads, the more P you have.  ;D


The first station I picked up last week at the new 4-Land location was The Voice of Russia, apparently the New and Improved version of Radio Moscow (whose link leads there):

http://www.ruvr.ru/index.php?lng=eng

Even reads like their old propaganda. The broadcast had a very Cold War sound to it, including the 'Mailbag' part of the program. Didn't notice any hum on their transmitters, but the receiver was js'ed to a set of rabbit ears...

I would think we heard the three phase hum of 300 Hz, from Radio Moscows 50 Hz mains. This would be the residual ripple from the big rig power supplies, unless there was some phase unbalance in the feeds or the power supplies. Then we'd hear some 50 creeping in. Anyway, I completely forgot that sound til ya'll mentioned it. Sounds and smells are some of the best memories I have left...

like a fart pipe on a honda civic

I always like The Voice of Communism best.

I wonder if i can rig up a Kerchunk^tm to work in Skype
they need to add a PTT feature anyway

Now....lets talk about something really important.....like Communism!

That's right.

that's right.

How about open headers barking fire on a cold winter night.....

G's already done that, Blaine. Think he uses a flyswatter on cue.  ;D


I had a little 70-something Chevy pickup with a 307 and three-on-a-tree with headers, header mufflers, and straight pipes out the side. You could see the flashes at night in the side view mirrors. Loved downshifting on a hill. Snappity-snap-snap-crack-crackle....

On both AM and ssb, I went the other way.  The key-up relays in the shack were just too damn loud and seemed acoustically amplified by the rack cabinet.  On ssb guys would axe me what the heck the sound was, since I like to use PTT to simulate VOX and key on and off frequently..

The solution was to build a low-level variable time delay that let me delay audio by about 250 ms before going live. The big relays now have time to acoustically die off and now there's just a slight blower noise coming up. 

Heck, a little blower noise and a look at the S meter is all someone needs to know they are listening to a really big mawl anyway, caw mawn.

T

I used the think my NC-183 was really sensitive in 1958 when I first heard "This is Radio Moscow" while my parents were in the other room watching "Bonanza" on the "one-eyed monster".

I miss the ol' 3 on a tree.  Always a non-synchro First, and Second was a good reach up and usually accompanied by copiuous amounts of gear whine.  But your center front passenger didn't have to deal with the shifter knockin' the nads or your elbow hittin 'em in the gut.

"How the hell are you driving that thing with it in Park??"

heh-heh...

Reminds me - There was a time in 1967 where I was a part-time car delivery guy for a car dealership.  One day I had the job of driving the company V8 Chevy pickup truck with three on the tree. On the return trip my buddy rode with me and I just had to impress him with my "power shifting," especially from first to second gear.

I held the gas pedal down and rammed the stick into second gear as the handle broke clean off at the linkage fork pin. Looked like an amputee.  I was mortified and my buddy just laughed like heck. We had to hobble our way back to the shop in second gear.

My buddy hopped out of the truck quickly, saying he didn't want no part of it. I had to walk in and tell the manager what happened - rather, the linkage got jammed in reverse in the parking lot and I pushed it too hard... :-0

He immediately put a mechanic on it and replaced the arm.  I could tell he knew what really happened. I got fired about a week later for another vehicle episode which I will not get into right now... :-)

T

I am glad someone thinks 50hz Hum is exotic - hang on while I hang a clip lead off the mic leads...

                                                                               Ian VK3KRI.

50~ has a distinctive sound in N. America since our power is 60~.

Here (http://en.wikipedia.org/wiki/List_of_countries_with_mains_power_plugs,_voltages_and_frequencies) is list of a.c. power frequencies in countries worldwide.

oh geez.. noise toys just like on the CB. Hmm.. lemme see if I can get the "mule fart" module to work with the kenwood. There is a VC-100 around here somewhere..

It's all well and good just for fun, but I'm proud of the noises my radios make naturally. The noises should come naturally and the envelope of the keying-up should reflect their origins, even if the rig has to be engineered to enhance them. Please let's not cheapen the true radio noises with imitations.

There's nothing like the smooth uptake of a dynamotor set, or the grunt of a very large set that keys the primary of the choke input HV PS.

That's right.

(that's right)


http://www.amwindow.org/misc/av/vocshort.mp3

I came close to losing my kerchunk.

When my second contactor started mis-behaving a friend donated a really nice 50A mercury relay.  I spent half the day Saturday installing it in my 8000 rig and hardly got a puff.  In fact, you have to hold your ear right up to it to even hear it.

The good news is that I had to take it out because the un-key time was so long that I feared for the rest of the rig.  For nearly half a second, the HV is still on with the exciter and antenna long gone.

I ended up making a few other changes and putting the old one back and it seems to be working and kerchunking again.

The actual problem seems to have been caused by one or both of, an 866 flashing over and a solid state delay relay that I use in the control circuitry that waits 400 ms after key down to turn on the HV. 

Having said all this, we had a discussion on the NTF Friday wherein one of the fellows suggested that the big bang has nothing to do with contactors or acustics at all.  It is the inductive spike on key-down that modulates the RF.

Any thoughts?

js

Disconnect your mic and try it.

That inspiring thought occurred to me today.  I did and it didn't.

Duh!  So much for science.

js

It didn't what? The kerchunk didn't go away or it did when the mic was disconnected?

This is a slightly delayed response BUT I could never speed shift with three on a tree. The linkage would lock up between gears and I would have to pullover to fix.
And Bonanza was the great beginning the famous NBC Peacock for color TV.
A color TV standard
Stereo TV sound
FM stereo
The few things the FCC did right.
We squeeked through a standard for HDTV. We couldn't do it the Japanses way. Too much bandwidth


Fred

It didn't kerchunk when with the audio turned off.

js

Thanks. That's what I would have bet on. Most of the kerchunks I hear have a live, acoustical sound to them, indicating they are coming through the mic. An inductive kerchunk would be more of a thump. You can also get a thump from your receiver's AGC reacting too.

I worked with Japanese HDTV at Sony. Ours here is no match for it on a 2000 pixels wide CRT based display system. We would tweek the VPH-1292 3-CRT projector for an hour before the demo. Even so we got the short end of the stick.

thought this might be of interest for those desiring the ker-chunk but using solid state relays.
http://www.musicfromouterspace.com/index.php?page=HOME

looks like PAIA lives on ....ohweeeeou ching ching ... beefus

Wow , thanks for the neato flatulence generator site.

Here's the one we should all get and trade effects on air, ca-mawn.
http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/WSG_Reborn/WEIRDSOUNDGENERATORREBORN.php (http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/WSG_Reborn/WEIRDSOUNDGENERATORREBORN.php)

Here's how I quieted my antenna changeover relay.  The springs came off a couple of old boom mounted workshop lamps I pulled out of a dumpster.  The wooden box has a door that, when closed, muffles out almost all the sound.  Otherwise I wouldn't be able to stand the sound of the thing clanking and buzzing.

and not definable as music by the fcc. yet. My object was not noise toys, just the quest for approriate transmiter sounds.

dynamotor spin-up
360Hz or 180Hz hum to imply 3 phase
large motor-generator spin-up
kerchunk
thump/oomph (power supply charging)

although flatulence is a normal operator sound.

Did you know that the South African hams can legally play music on the air?

Is that what I hear on 3.925 Mhz AM sometimes? South African hams? hmmm....

I think that is a broadcast station in Papua New Guinea. They have been there for years.  Audible in the morning.  It would be a daylight path to S.A. at that time.

No. SA hams are limited to below 3800 kHz.

That website reminds me of the type of projects one would see in Popular Electronics back in the 70's and 80's before PE went TU.

From the South African ham rule book.

B7  MUSIC TRANSMISSIONS 

No form of entertainment shall be transmitted from an amateur radio station: Provided that music transmissions for experimental purposes shall be

Permissible on condition that-  

a) such transmissions shall last no longer than three minutes;

(b) at least five minutes shall elapse before any further music is transmitted from the same station.

(c) when commercial recordings are used the make, name or title of such recordings shall not be mentioned; and

(d) such transmissions shall not take place in bands other than the following:

(i) 3 500 - 3 800 kHz
(ii) 50 - 54 MHz
(iii) 144 - 146 MHz (iv) 430 - 440 MHz
(v) 1 240 - 1 300 MHz


That's perfect for a music QSO with three stations!!!

A true work of art there!

Pretty funny stuff in this thread - I was giggling so hard, the tears were rolling down by cheeks.

I seen to recall Irb VJZ had a loud SNAP!! when he went to transmit on his DX100 followed by some squealing, but this may have only been on his 10M transmitter.

thought of this topic for some reason, maybe the potatoes in the Tucker are too small. anyway, some things got scrounged up of the shelves and put on the bench to experiment with.

1. a synchronous motor driven frequency generator. This makes 90Hz and 150Hz sinewaves simultaneously at 7 volts using a small alternator. On 120V it starts very quickly, hardly any spool-up time, needs more investigation. Also, would the 90 and 150Hz be heard A La Voice of Moscow II? maybe. It can be seen in the photo of the spring reverb. I have no idea what this was from. Was too cool to be thrown in the scrap dumpster and has been around for a decade.

2. a spring reverb aftermarket kit from Sears. Germanium dirt. 2 springs.

3. a Beringher frequency shifting pedal.  - best kept for the mic?

4. contactors - -too PW for mounting in air, but maybe on a sounding board might do OK. It could be possible to mount an 8-ohm speaker to the sounding board and let it pick up the contactor noise electronically.

if these things were sequenced by relays, it could get amusing.

key up with reduced screen voltage to the PA, @ 1/2 carrier.
1/2 second delay to give the listeners' s-meters time to settle.
bang with spring echo from the contactor on the board, contactor bumps up the screen volts to normal for that stepped-power effect and also spins-up the 90/150 Hz MG set for that RM background sound.

analog sickness at it peak.

I have heard various key up sounds, most were interesting, but background blowers just sound nasty.
Hum is fine, relays/contactors are fine, but blowers just suck.

Someone years ago had a clock ticking loudly in the background, I remember hearing lawn mowers running in the background, aircraft flying over, I don't hear much of that sort of thing anymore.

Better compressors with thresholds?


Brett

Agreed but the only blower you will here with the "key up" is your own.

Jack

I use those 24V furnace? relays with 20A contacts for all RF T/R-ing the shack. Quite a racket on key up in the shack. But my key-up on the air is as quiet as a butteryfly. How do you do it, Tom Vu?  I use a 250 millisecond delay in the audio so that the loud relay clack has already decayed when audio is applied. I do the same on ssb.

Normally, a key-up clack on AM is not so bad - but on ssb it's abominable. When doing ssb PTT with fast comments, a quiet key-up is needed.

Yes, vacuum relays are the best way to do it, but a second cheaper way is the slight audio delay.  Use a 555 timer that has an adjustable attack R/C and drive a small (quiet) relay that makes and breaks the audio at the 1 volt (high-level) point in the audio chain.  Works like a charm.  

I have a switch to enable instant audio key-up when I want to join in with the AM "clacker boys" ... ;D

(hmm.. just looked back at this old thread and see I already said this on page 2 - well, here it is again in fine Old Buzzard fashion)

T

Agree on the blower sound

Irvine Vermilia  W1ZE  used to do the clock sound I liked it

Here's his QSL - Oh yeah, I misspelled his name -- oh well.

http://www.bostonradio.org/essays/vermilya

OK OK  One more article

http://earlyradiohistory.us/1917verm.htm

Al

Just a 'clack' is annoying. To really sound like a power house it will need that 300mS of exponentially decaying 60Hz as the transformer surge settles down. If you're gonna have a spud in yer shorts make sure it's a big ol' Russett, not some "New Potato"  yuppie nibble.

73,
Mark

my tube likes the sound of a blower

When I get my rig built, I want the sound of an ARC LAMP searchlight or a Spark Gap transmitter as an intro. ;D

When I lived in Burton Mich. as a youngster,they had a searchlight in the Car Lot at the corner. 

It had such a neat FIZZING/Crackling sound to it. 8)

Good suggestion on the decaying 300ms of 60Hz. That's the groan of iron!

There is also a nice motor-generator-like sound in the movie "TXH1138" where he restarts the turbine-electric car and takes off.

The "PING", and a bit of feedback from a Browning Golden Eagle. Thats real POWAH........

I like the sound of Tron's relay "clack!" and the blower (muffin fan?) winding up slowly at the beginning of each transmission.  The fan drops into the background not to be heard again during one of his legendary buzzard transmissions on doing a mod on a transmitter completely from memory.

Al

I currently have an ad running on craigslist for a hunchbacked lab assistant. I shall call him Igor and already have a large six foot knife switch mounted on a large oak board. His only job will be to watch me key up and simultaneously throw the big knife switch ... just to make the sound.

I'm pissed Marty Feldman is dead. He would have got the gig.

(http://1.bp.blogspot.com/_K5ls3SJu5Qo/Suu-TDOjbkI/AAAAAAAAB4s/wHcuCpqFa6Q/s320/Marty+Feldman+and+Abby+Normal.jpg)

John

What's the job pay?