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Tinkerer <tinker5@anytime.net>: Feb 28 04:27PM -0500 I have a Heathkit ET-3100 electronic design experimenter that has a very basic sine/ square wave function generator. Controls all analog and no scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 Khz on "high". Exact frequency depends on where the pot is adjusted. How can I calibrate this to be more precise, preferably in a simple way?

"ohg...@gmail.com" <ohger1s@gmail.com>: Feb 28 01:50PM -0800 On Sunday, February 28, 2021 at 4:27:15 PM UTC-5, Tinkerer wrote: > scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 > Khz on "high". Exact frequency depends on where the pot is adjusted. > How can I calibrate this to be more precise, preferably in a simple way?   Frequency counter. They have cheap Chinese kits on ebay that should give you readings close enough to what that generator would be used for.

Phil Allison <pallison49@gmail.com>: Feb 28 02:53PM -0800 Tinkerer wrote: ============== > scale really. Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 > Khz on "high". Exact frequency depends on where the pot is adjusted. > How can I calibrate this to be more precise, preferably in a simple way?   ** Time to get a Digital Multimeter with a frequency range. Not crazy expensive and damn useful. Plus very accurate.       ...... Phil

gray_wolf <g_wolf@howling_mad.com>: Feb 28 09:25PM -0600 On 28/02/2021 3:27 pm, Tinkerer wrote: > Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 Khz on "high".  Exact > frequency depends on where the pot is adjusted. How can I calibrate this to be > more precise, preferably in a simple way?   Borrow a freq counter?

Abandoned_Trolley <fred@fred-smith.uk>: Mar 01 11:08AM On 28/02/2021 21:27, Tinkerer wrote: > scale really.  Output is from 200 Hz - 2 Khz on "low" and 2 Khz to 20 > Khz on "high".  Exact frequency depends on where the pot is adjusted. > How can I calibrate this to be more precise, preferably in a simple way?     One of those cheap digital guitar tuners things might point you in the right direction ? (everybody knows somebody who plays the guitar)   I believe there are smartphone apps which display the frequency of the signal coming in to the microphone - whilst recording it. Theres one (of many) examples at https://audio-frequency-counter.soft112.com   Or if you know anybody with Cubase (or similar) recording software you could get them to fire up the built in digital tuner tool and see it in glorious technicolor   AT

Chris Jones <lugnut808@spam.yahoo.com>: Mar 01 10:58AM +1100 On 01/03/2021 03:16, Peter W. wrote:   >> As long as it does not actually get charged before or during the time >> that it is near the sensitive circuitry, it should not cause damage.   > There is a very long stretch between "should not" and "will not". When the proper means-and-methods are readily available, one *should not* take the lesser path.   Ordinary insulating tapes can be used in the proximity of ordinary electronics, and it would be misleading to claim otherwise. If the circuit includes small-signal mosfets with unprotected gates, then I would consider taking more precautions, but those have been uncommon for many decades.

Chuck <chuck23@dejanews.net>: Feb 28 12:23PM -0600 On Sat, 27 Feb 2021 12:27:16 -0800 (PST), "ohg...@gmail.com"   >> Then there is this quad unit, outputs good but it had more bad transistors than you could sweep off the floor. get the amp fixed and a channel is cutting out. Bad connection ? Nope, a transistor. Got that fixed and now off to another board that is no doubt full of bad transistors.   >> Life is trip, think of the destination.   >The only time I really remember transistors being a red flag (other than early Germaniums) were some small Hitachi signal transistors from the 70s-80s - the TO-92 ones with the beveled top. Those things would go leaky or open or intermittent (their choice). It got to the point back then that I just automatically changed them whenever I saw one in anything I worked on. Pretty much eliminated any rechecks.   It was the 2SC458s.

Phil Allison <pallison49@gmail.com>: Feb 28 12:07PM -0800 ohg...@gmail.com wrote: =======================   > The only time I really remember transistors being a red flag (other than early Germaniums) were some small Hitachi signal transistors from the 70s-80s - the TO-92 ones with the beveled top. Those things would go leaky or open or intermittent (their choice). It got to the point back then that I just automatically changed them whenever I saw one in anything I worked on.   ** You talking about the the dreaded " black leg corrosion" problem ? TO92s and the like with silver plated leads.   Silver sulphide would form on the plating, travel into the device and eat the chip.   Always Jap stuff like Marantz.   ..... Phil

Fox's Mercantile <jdangus@att.net>: Feb 28 12:04PM -0600 On 2/28/21 7:09 AM, bruce bowser wrote: > Cut it too long, the boss might gripe. Cut it too short, you're fired.   On one of the install jobs I was on, we had just pulled a 24 pair fiber optic cable. The installer connected 12 pairs to the devices already in the cabinet. The proceeded to cut off the remaining end flush with the box. "They were in the way."     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

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