Opamp frequency mixer

On 7/5/2015 7:16 PM, Clifford Heath wrote:
> On 06/07/15 12:18, bitrex wrote:
>> On 7/5/2015 12:39 PM, Clifford Heath wrote:
>>> On 06/07/15 02:22, Clifford Heath wrote:
>>>> On 05/07/15 07:06, Jim Thompson wrote:
>>>>> On Sat, 04 Jul 2015 13:53:15 -0700, Joerg <news@analogconsultants.com>
>>>>> wrote:
>>>>>> On 2015-07-04 1:30 PM, bitrex wrote:
>>>>>>> Can anyone suggest an opamp mixer topology for the low 100s of kHz?
>>>>>> If it absolutely has to be semiconductors I'd use the MC1496.
>>>>> I'd go with the MC1494... if you can get it.  It has the level
>>>>> shifting built-in... quite adequate for audio, and immensely eases the
>>>>> pain of doing your own level-shifting.
>>>>
>>>> If you can't get MC1494 but can arrange one bipolar drive signal, you
>>>> can make the rest of a Gilbert cell very easily using the matched
>>>> transistors in a LM3046, which are readily available, cheap and
>>>> sufficiently retro. You even get a spare transistor you could use for
>>>> the phase splitter.
>>>
>>> Forgot to mention, the Ft of the LM3046 is circa 350MHz, so no problem
>>> operating at HF. And there's always the rather faster and more expensive
>>> HFA3101 if you need to operate up to 1GHz :). But the LM3046 is one of
>>> my jelly-beans for discrete stuff up to 50MHz. It can go higher, but
>>> it's less trouble to design using faster transistors.
>>>
>>
>> Unfortunately, however, it seems like the MC1494, 1496, LM3046, and so
>> on are all non-stock just about everywhere.
>
> LM3046 is available in heaps of places, and used in lots of designs so
> is likely to be manufactured for some time. Use the SMT versions. I was
> thinking of a circuit like this one. The input transformer does the
> phase splitting and provides the low impedance you need. You can ground
> either of the other inputs for single-ended, and ignore either of the
> outputs:
>
> <https://www.dropbox.com/s/bvql4eii5w3g33n/LM3046%20mixer.pdf?dl=0>
>
> No need to sign in or sign up to Dropbox, just cancel on through to the PDF.
>
> Clifford Heath.
>

Thanks!

On 2015-07-05 9:44 PM, Phil Hobbs wrote:
> Digikey shows 6000-odd of the MC1496 in stock. http://www.digikey.com/product-detail/en/MC1496DR2G/MC1496DR2GOSCT-ND/1139685?WT.z_cid=ref_octopart_dkc_buynow&site=us
>

Arrow even has them in DIP but hurry, they are EOL'd and they've only 
got about 10,000 of them :-)

http://components.arrow.com/part/detail/40219439S7075697N1952?region=na&utm_source=FindChips&utm_medium=invListing&utm_campaign=FC2015

Of course, they may not be retro enough for this project because they 
don't come in a glass package and nothing glows.

-- 
Regards, Joerg

http://www.analogconsultants.com/

>Arrow even has them in DIP but hurry, they are EOL'd and they've only 
>got about 10,000 of them :-) 

I already bought four tubes of them, so Arrow's are safe for now.  ;)

Cheers

Phil Hobbs

"Joerg" <news@analogconsultants.com> wrote in message 
news:d0285kFmdegU1@mid.individual.net...
> Arrow even has them in DIP but hurry, they are EOL'd and they've only 
> got about 10,000 of them :-)
>
> http://components.arrow.com/part/detail/40219439S7075697N1952?region=na&utm_source=FindChips&utm_medium=invListing&utm_campaign=FC2015
>
> Of course, they may not be retro enough for this project because they 
> don't come in a glass package and nothing glows.

Check Richardson's stock, maybe they have some that glow!  :^)

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com