[ARC5] BC-348Q CW Oscillator Question

[John Hutchins]

Gentlemen -

Taking a look at the schematic, with the CW switch off,  the plate pin 
resistance to ground should or better be infinite.  Or the capacitor 
(14), or gimmic cap is leaking?

I would say the measurement seems right since wiht the switch closed 
there are 1 35K resistor (97-0), followed by 2, 1meg resistors (87-3) 
(87-4),  in parallel to ground, thats ~500K + ,on the power bus, that 
feeds the BFO on off switch.    If pins 2, 6 are shorted on the back 
plug it might be a bit less that 500K - .

Hutch

On 1/12/2016 10:33 PM, WA5CAB--- via ARC5 wrote:
> I agree that the Switch-Off reading should be quite high.
> The chart doesn't actually say, but did you take your Switch-On 
> reading with a dynamotor connected or disconnected?
>
> In a message dated 01/12/2016 20:29:24 PM Central Standard Time, 
> arc5 at mailman.qth.net writes:
>> If that's what the circuit DC path shows, and the CW osc works,I 
>> wouldn't worry about it. Probably is a typo.
>>
>> I was never fond of wholesale resistance measurements as a 
>> troubleshooting tool anyway. Are you just poking around or is there 
>> an issue with it?
>>
>> On Tuesday, January 12, 2016 6:50 PM, Mark K3MSB 
>> <mark.k3msb at gmail.com> wrote:
>>
>> Gentlemen:
>>
>> I'm restoring my BC-348Q receiver.   The resistance measurements I 
>> get for the Plate (Pin 6) of the 2nd Det / CW Oscillator tube (V233) 
>> are way off.
>>
>> Table D from AN-08-10-112:
>>
>> CW OSC OFF:  500K
>> CW OSC ON:   5M.
>>
>> My measurements:
>>
>> CW OSC OFF:  Infinite
>> CW OSC ON:   600K
>>
>> >From sketching out the DC circuit path from V233 Pin 6, I come up with :
>>
>> CW OSC OFF:  Infinite
>> CW OSC ON:   567K
>>
>> I'm wondering if the manual has the values flipped?
>>
>> 73 Mark K3MSB
>>
>>
>>
>>
>>
>>
>>
>
>
> Robert & Susan Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
>
>
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