[time-nuts] Austron/ Systrom Donner 8181 Time Code Reader
tmiller11147 at verizon.net
Sun Apr 23 16:24:23 EDT 2017
If you know what the zener is and what the unregulated supply voltage is,
you should be able to calculate the resistance and power.
----- Original Message -----
From: "Dave Wood" <w4ej15 at gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Sunday, April 23, 2017 2:31 PM
Subject: Re: [time-nuts] Austron/ Systrom Donner 8181 Time Code Reader
> Bill, actually what happened is the zener diode that the resistor fed
> shorted and that's the reason it burned up. I have two units with this
> issue and I cannot read the resistor value since it burned up. What I
> would love to know is what the original value of the dropping resistor
> was? 73 Dave
> On Sat, Apr 22, 2017 at 11:39 PM, Bill Hawkins <bill.iaxs at pobox.com>
>> There is usually a power dissipation reason why a resistor becomes
>> toast, and the reason is frequently a shorted bypass cap or a shorted
>> Have you measured the resistance to ground of the end of the resistor
>> opposite the power supply?
>> Sometimes inputs get high voltages and short the amplifying device.
>> Sometimes that is reason the units were for sale.
>> Hope I'm wrong.
>> Bill Hawkins
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Dave
>> Sent: Saturday, April 22, 2017 8:43 PM
>> Anyone on the list own the above Time Code Readesr. I have one of each,
>> they are identical with the same issue. I need to identify the correct
>> value of a resistor in the power supply that provides 27 volts to the
>> input amp. They are both toast in my units and I do not have a manual.
>> Thanks in advance! Dave _______________________________________________
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