I can, but first, you realize that this is nothing more than a bandwidth check and a very crude one?? Your function generator ought to go to to 10 Mhz or so.
If it does triangle waves, you can use a triangle instead of a square (just different harmonics but still needs them).? If the triangle starts to round with 20 Mhz bandwidth in, and is reasonably sharp at 20 Mhz bandwidth out, then you've done the same thing.
If the bandwidth is limited, then you'll see that the triangle looks a lot like a sine instead of a proper triangle.
You don't absolutely need a schmidt trigger, I'm just being a purist.
What PC board layout programs do you have?? They have schematic capture.? Kicad is one.? I personally use an old version of EAGLE, so I could deliver this to you as a picture without you having to do anything.
First, though, how high a frequency can your function generator do?
Harvey
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On 10/15/2023 3:20 PM, Walt KA2NJF via groups.io wrote: Harvey,
Can you draw that up for me. I have to be very careful since my right hand shakes when it wants to. I do have a plug in breadboard that I can use. The Schmidt trigger chip I will look a see if I have any. If not then I will purchase some.
Walt
Sent from the all new AOL app for iOS <>
On Sunday, October 15, 2023, 12:44, Harvey White <madyn@...> wrote:
Can you breadboard TTL?
1K in series, 5.0 volt P-P sine wave, diodes to VCC and GND to limit
what the gate input sees, use any schmidt trigger (74LS14, etc) to
produce a pulse output, then run that through a few gates (same
package)
to neaten it up, and you have an emergency square wave generator.
Harvey
On 10/15/2023 12:19 PM, Walt KA2NJF via groups.io wrote:
> Harvey,
>
> My WaveTek does not support square wave generation.
>
> Walt
>
>
> Sent from the all new AOL app for iOS
>
<>
>
> On Saturday, October 14, 2023, 13:51, Harvey White
> <madyn@...> wrote:
>
>? ? Ok, how fast is the wavetek signal generator?
>
>? ? if it's at least 2 mhz, and can put out a square wave, then
try that.
>? ? You're looking for significant edge rounding at any frequency
from
>? ? 2 Mhz
>? ? on (the higher, the more rounding) in the 20 Mhz position.
You need
>? ? about 10x the bandwidth to reproduce a decent square wave.
i.e. 2 Mhz
>? ? needs 20 Mhz bandwidth because of the harmonics that make the
square
>? ? wave square.? That's why I suggested something around 10 to
20 Mhz.
>? ? You'd be able to see the effects.? The closer to the 2 Mhz
you get
>? ? (and
>? ? below), the less you'll see the effect of the bandwidth.
>
>? ? See if tek WIKI has the service manual.
>
>? ? If you can breadboard a TTL oscillator, that might help. Same
>? ? restrictions on frequency.
>
>? ? Harvey
>
>
>? ? On 10/14/2023 12:02 PM, Walt KA2NJF via groups.io wrote:
>? ? > Harvey,
>? ? >
>? ? > The test equipment I have is:
>? ? > 1. Wavetek Signal Generator
>? ? > 2. HP 410C VTVM
>? ? > 3. Sinometer Frequency Counter
>? ? > 4. Tel 2445 Scope
>? ? >
>? ? > It looks like I will have to purchase some more equipment if
>? ? funds let
>? ? > me !!
>? ? > I will remove the case and blow out the dust and look at
the fan. I
>? ? > will reoil it if possible.
>? ? > I don¡¯t have a service manual.
>? ? >
>? ? > Walt
>? ? >
>? ? >
>? ? > Sent from the all new AOL app for iOS
>? ? >
>? ?
<>
>? ? >
>? ? > On Saturday, October 14, 2023, 00:34, Harvey White
>? ? > <madyn@...> wrote:
>? ? >
>? ? >? ? I'd say anything between 10 and 20.? What you're looking for
>? ? is the
>? ? >? ? effect of the 20 Mhz bandwidth reduction. The higher the
>? ? >? ? frequency, the
>? ? >? ? more obvious.
>? ? >
>? ? >? ? Do NOT couple a transmitter directly into the scope, use
a dummy
>? ? >? ? load on
>? ? >? ? the transmitter, and pick up a signal with a wire loop.
SA's and
>? ? >? ? Scopes
>? ? >? ? cannot tolerate wattage from a transformer. You could use a
>? ? 5 Mhz
>? ? >? ? square wave and look for the edge to see how it changes,
that
>? ? >? ? works, too.
>? ? >
>? ? >? ? Harvey
>? ? >
>? ? >
>? ? >? ? On 10/13/2023 11:33 PM, Walt KA2NJF via groups.io wrote:
>? ? >? ? > Harvey,
>? ? >? ? >
>? ? >? ? > At the present time I have nothing to generate a 20
MHZ signal
>? ? >? ? with.
>? ? >? ? > Will it work with a 20 MHZ RF signal ??
>? ? >? ? >
>? ? >? ? > Walt
>? ? >? ? >
>? ? >? ? >
>? ? >? ? > Sent from the all new AOL app for iOS
>? ? >? ? >
>? ? >
>? ?
<>
>? ? >? ? >
>? ? >? ? > On Friday, October 13, 2023, 21:45, Harvey White
>? ? >? ? > <madyn@...> wrote:
>? ? >? ? >
>? ? >? ? >? ? Take a 20 Mhz square wave and look at it on 20 Mhz
>? ? bandwidth,
>? ? >? ? then
>? ? >? ? >? ? go to
>? ? >? ? >? ? full bandwidth.? If that doesn't give two different
>? ? results, then
>? ? >? ? >? ? that
>? ? >? ? >? ? tells you a lot.
>? ? >? ? >
>? ? >? ? >? ? Harvey
>? ? >? ? >
>? ? >? ? >
>? ? >? ? >? ? On 10/13/2023 8:07 PM, Walt KA2NJF via groups.io wrote:
>? ? >? ? >? ? > Davy,
>? ? >? ? >? ? >
>? ? >? ? >? ? > I have tried recycling all the switches, push
buttons, and
>? ? >? ? rotary
>? ? >? ? >? ? > switches with no change in the Tek 2445 response. I
>? ? even looked
>? ? >? ? >? ? for a
>? ? >? ? >? ? > master reset switch. I have tried recycling the push
>? ? buttons,
>? ? >? ? >? ? switchs
>? ? >? ? >? ? > and rotary switches on and off for the past three
or four
>? ? >? ? days. The
>? ? >? ? >? ? > last time I remember it working was a month or so
ago.
>? ? If you
>? ? >? ? >? ? come up
>? ? >? ? >? ? > with any more suggestions I am all ears.
>? ? >? ? >? ? >
>? ? >? ? >? ? > Thanks,
>? ? >? ? >? ? > Walt, KA2NJF
>? ? >? ? >? ? >
>? ? >? ? >? ? >
>? ? >? ? >? ? > Sent from the all new AOL app for iOS
>? ? >? ? >? ? >
>? ? >? ? >
>? ? >
>? ?
<>
>? ? >? ? >? ? >
>? ? >? ? >? ? > On Friday, October 13, 2023, 17:40, Dave Casey
>? ? >? ? >? ? <polara413@...>
>? ? >? ? >? ? > wrote:
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? Walt -
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? Is the 20 Mhz BW Limit pushbutton (located
directly
>? ? >? ? above the Ch2
>? ? >? ? >? ? >? ? Volts/Div knob) depressed? If it is not depressed,
>? ? >? ? perhaps the
>? ? >? ? >? ? >? ? switch has gotten dirty and cycling it a few
times will
>? ? >? ? resolve
>? ? >? ? >? ? >? ? your issue?
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? Dave Casey
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? On Fri, Oct 13, 2023 at 3:25?PM Walt KA2NJF via
>? ? groups.io
>? ? >? ? >? ? >? ? <>
<wmilton2359@...>
>? ? >? ? wrote:
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? ? ? Hey,
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? ? ? I just joined the group and my name is Walter,
>? ? >? ? KA2NJF I am 80
>? ? >? ? >? ? >? ? ? ? years old. My Tektronix is in need of
service. Is
>? ? >? ? there any
>? ? >? ? >? ? >? ? ? ? service deposit or any one in the South
Jersey or
>? ? >? ? South East
>? ? >? ? >? ? >? ? ? ? PA who works on this piece of equipment? I
can not
>? ? >? ? get any
>? ? >? ? >? ? >? ? ? ? frequency reading above 20 MHZ and this is a
>? ? 150 MHZ
>? ? >? ? scope.
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? ? ? Thanks,
>? ? >? ? >? ? >? ? ? ? Walt, KA2NJF
>? ? >? ? >? ? >
>? ? >? ? >? ? >
>? ? >? ? >? ? >? ? ? ? Sent from the all new AOL app for iOS
>? ? >? ? >? ? >
>? ? >? ? >
>? ? >
>? ?
<>
>? ? >? ? >? ? >
>? ? >? ? >? ? >
>? ? >? ? >
>? ? >? ? >
>? ? >? ? >
>? ? >? ? >
>? ? >? ? >
>? ? >? ? >
>? ? >
>? ? >
>? ? >
>? ? >
>? ? >
>? ? >
>
>
>
>
>
>
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