[time-nuts] HP10514B Mixer Terminations

[Brian Kirby]

That post had the drawing of the last system (2nd generation), just to 
show the setup I was using for the offset generator.  (LT1027 preamp).

The new system, which I was testing the mixer terminations, has the 
LT1028.  Its terminated in 150 pF, a 1 kilo-ohm series resistor and then 
a 0.1 uF capacitor, then the scope probe.  The LT1028 is disconnected an 
unpowered for these test.

I tried something this evening, I used some trimmer capacitors and I got 
best square wave at 156 pF....xC at 20 mhz = 51.0 ohms....interesting.

I'm beat and I got to go back to Talladega tomorrow morning, so I'm not 
going do any more experiments this evening.

Brian

Bob Camp wrote:
> Hi
>
> If you are just changing C1 when you go to 150 pf, the mixer is still pretty heavily loaded by R1 and C2. The mixer is only "close" to open circuit with R1 (or R1 plus a coil) at 500 ohms.
>
> Bob
>
> On Mar 30, 2010, at 7:55 PM, Brian Kirby wrote:
>
>   
>> Here's a block/schematic of the last version I reported on last night.
>>
>> Brian Kirby - KD4FM - Guntersville, Alabama
>>
>> EWKehren at aol.com wrote:
>>     
>>>   Good morning Brian.
>>>
>>>   What do you use as an OFF SET oscillator?
>>>
>>>   Thank you
>>>
>>>   Bert Kehren  Miami
>>>
>>>  .
>>>       
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