[time-nuts] Balanced Mixer App Note

Bob Camp lists at rtty.us
Sat Mar 27 20:44:22 UTC 2010


Hi

It should be easier to DC screen individual diodes for flicker noise than RF test full mixers.. 

That of course *assumes* that there's a correlation between baseband and RF.

Bob


On Mar 27, 2010, at 4:32 PM, Bruce Griffiths wrote:

> The potential advantage is that a typical 10514 using discrete diodes is about 6dB quieter than a typical RPD-1 using a monolithic quad in the flicker noise region.
> 
> Bruce
> 
> Bob Camp wrote:
>> Hi
>> 
>> You often see reels of parts on the auction sites at crazy prices. Somebody scrapped out a through hole pick and place loader and is selling off the inventory that was still in place. I've often though the one could get lucky and find a reel of rational diodes without spending a lot of money on them.
>> 
>> Setting up to do the basic sort is definitely "basement compatible" sort of stuff. The tail end of the process would be to drop candidate quads into a fixture and see how they actually do in a real mixer. Still something you could do in the basement.
>> 
>> The transformers you would wind are going to be a lot bigger than the ones MiniCircuits uses. I don't think that would be a problem in any most time nut basement settings.
>> 
>> Bob
>> 
>> On Mar 27, 2010, at 12:34 PM, Magnus Danielson wrote:
>> 
>>   
>>> Ulrich Bangert wrote:
>>>     
>>>>> It's not real clear that building a part with monolithic diode pairs or quads buys much over a part from MiniCircuits.
>>>>>         
>>>> Rumours are that the famous HP10514 is made from 4 discrete hand selected
>>>> diodes. If you have thousands of diodes to select from building your own
>>>> mixer may give sense.
>>>> 
>>>>       
>>> Well, the HP10514 does have 4 individual diodes. Selection is certainly being done.
>>> 
>>> Using selection for other home-built stuff is done regularly in the Synth-DIY world, so it is not too hard to do. Modern mixers use either the same die or at last dies from the same place of the wafer to accomplish close matching.
>>> 
>>> Cheers,
>>> Magnus
>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> 
>>>     
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
>>   
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 




More information about the time-nuts mailing list