Re: Amplifone HV problem

We are down to just one left of the FBT ring testers, should be more in
soon...
They are handy if you have a number of HV or other monitors to test. For a
single user, I don't know...do you want to pay to know your flyback is dead
or alive? On the WG I just look at the flyback. If it is cracked or stuff
is oozing out, then I assume it is bad...

The tester is very simple, it just sends out a pulse and the number of
rings you get back is shown on a LED display, six or more assume the FBT is OK.

<theory>
Before I used started carrying this tool, I would just get out an old audio
signal generator and crank it up to the flyback's resonate frequency, then
hook up a scope to one of the other lines and look at the picture. If the
voltage was correct (that is if it was the correct ratio) then the flyback
was good. If the voltage was low or missing then the flyback was toast.
This would work even if the audio oscillator couldn't put out more than 10
volts @, say, 15kHz. One could also measure the DC output, again the ratio
was what mattered.
</theory>

Hope this is ok, for the list...

John :-#)#

At 11:55 PM 9/29/1999 -0400, you wrote:
>In a message dated 9/28/99 11:58:14 PM Eastern Daylight Time,
>acmech@erols.com writes:
>
><< I have a Red HVT in there. Does this sound like a bad HVT. I'm just
>wondering if
> I should go out and get a 24v regulator or can the reg be good and
> something
>is
> pulling down the volts?
> >>
>
>Have you tried ringing the HVT out?? John @ John's jukes sells them, they're
>great. You also might want to pull and check your MPSU07, if it's gone, I
>allways use an SK3199 s a replacement.
>Are you getting a waveform at the base of the BU406D??? You will continuously
>blow BU406D's ($) if you don't have a waveform there. Check also to see if
>your 555 is putting aout a waveform.

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Received on Thu Sep 30 01:59:37 1999