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RF mixer IC recommendation

Discussion in 'Electronic Design' started by Paul Burridge, Feb 21, 2004.

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  1. Anyone care to nominate an RF mixer chip for <100Mhz that's readily
    available in the UK?
     
  2. John Jardine

    John Jardine Guest

    LM1496
     
  3. maxfoo

    maxfoo Guest


    give 'em a call for free samples...


    EUROPE
    Hittite Microwave Europe Ltd
    Sales and Applications
    4.1 Intec Wade Road,
    Basingstoke Hampshire,
    RG24 8NE,
    United Kingdom

    E-Mail:
    Phone: +44 1-256-817-000
    Fax: +44 1-256-817-111













    []



    Remove "HeadFromButt", before replying by email.
     
  4. Leon Heller

    Leon Heller Guest

    What sort of performance is required? Diode mixers are easy to obtain
    and have good IMD characteristics. The impedances on the ports need to
    be properly matched.

    Leon
     
  5. "Good." :)
    What - the sort of crossed diode config one often sees in the ham
    design books? Do you think I might as well just make one up from
    discretes? I'm basically just trying to combine 60Mhz with 20Mhz to
    end up with the difference frequency in this case. JJ suggested a
    chip, but looking at the data sheet, it seemed to be designed more as
    a modulator than a mixer. Let's not get into an argument over
    semantics but y'all know what I mean, I'm sure.

    BTW, thanks for a good steer with the Pulsonix suggestion, Leon. I'm
    making good progress getting to grips with it.
     
  6. Frank Dinger

    Frank Dinger Guest

    Anyone care to nominate an RF mixer chip for <100Mhz that's readily
    ================================
    SA602AN as well as SA612AN each costing GBP 2.50
    Both have on-board LO circuit.
    www.modecomponents.co.uk ,probably also from www.jabdog.com
    Both companies are in the Birmingham area.
    If you are a member of G-QRP Club the SA602AN is somewhat cheaper from Club
    Sales.

    Frank GM0CSZ / KN6WH
     
  7. Tim Wescott

    Tim Wescott Guest

    The Philips SA602 or SA612 ought to be available in the UK. Don't overload
    the RF port though, the gain folds back over 200mV RF input -- confuses the
    hell out of an AGC loop.
     
  8. I do this with a dual gate MOSFET, osc on second gate, signal on first.
    A voltage divider on gate 2 to set it in teh non-linear part.
    This works very well, is not critical, very cheap and extremely reliable.
    Also the noise figure is good.
    So tuned 40MHz in drain
    I did one some weeks agao, but cant remember what that was for?
    Anyway that sceme works up to a GHz , from kHz up.
    If you need diagram and part example I could draw up one here.
    Copyright Jan Panteltje 2004 All Right Reserved
    By reading this you agree to pay me 1 fc.
     
  9. Leon Heller

    Leon Heller Guest

    You could make your own, but an MCL TUF-1 or SBL-1 won't be all that
    expensive. They do need a 7 dBm local oscillator drive level.
    You could join the Pulsonix UG:

    http://groups.yahoo.com/group/PulsonixUG/

    Leon
     
  10. Since you don't specify anything important like IP3, my recommendation
    is Siemens S042P. Earlier, when Motorola was easy to buy from, I would
    have used MC1496P, but none of them have high IP3 and I suppose NE602
    isn't any better. If balance isn't important, I would use BF905 or
    BF199

    73, LA8AK
    http://home.online.no/~la8ak/
     
  11. Thanks. I'll check 'em out.
    Will do. There are a couple of minor queries that have arisen.
     
  12. SWbeginner

    SWbeginner Guest

    Do the dual gate mosfets outperform the NE602 with regards to IP3?

    For some reason the NE602 refuses to oscillate with crystals but LC's are
    OK.
     
  13. Jim Thompson

    Jim Thompson Guest

    [snip]

    The NE602 only supports Colpitts and Butler crystal oscillator
    configurations. It is *not* an inverter-style oscillator.

    See:

    http://www.semiconductors.com/acrobat/applicationnotes/AN1983.pdf

    ...Jim Thompson
     
  14. here is the first mention of IP3 in the thread, I've asked whether it
    is important or not, but have not received any confirmation and will
    therefore not comment. If IP3 was said to be important I am aware of
    other mixers, and have used some douzens SBL1, SBL-1X, CM-1, SRA1 and
    other since 1977. A very easy mixer to use is TBA120=SN76660N.

    I usually construct to requirement, not what somebody else think is
    fine

    73
     
  15. If you have a very high-Q tunable front end filter, you usually get
    away with a mediocre IP3. However, if wide open (1 octave) front end
    filters are used, you would benefit from a high IP3 if you are using a
    decent antenna.

    If you try to receive the 7000 .. 7100 kHz amateur band in Europe,
    with 100-500 kW broadcast transmitters every 5 kHz starting at 7105
    kHz, the input IP3 number would have to be at least 20 dB higher than
    the strongest broadcast signals or even 30 dB higher if you try to
    receive QRP stations.

    Attenuating the whole antenna signal with a passive attenuator will
    also rapidly drop the IP3 products, but sooner or later the weak
    desired signal will be lost in attenuator thermal noise.

    Paul OH3LWR
     
  16. Can someone kindly confirm what the hell "IP3" is?? I can only think
    of "3rd order intermodulation products" which might easily be
    completely wrong. It would be helpful if whoever first uses an
    uncommon abbreviation would have the courtesy to state what it meant!
    (as is customary first time around)
    <snarl, hiss, etc>
     
  17. Jim Thompson

    Jim Thompson Guest

    It's only an "uncommon abbreviation" to certain Brits who think they
    can learn by insulting the masters ;-)

    Look up 3rd order intercept point.

    ...Jim Thompson
     
  18. Roy Lewallen

    Roy Lewallen Guest

    I agree it's discourteous to use an uncommon abbreviation without
    explanation. But IP3 is a very common abbreviation when discussing mixer
    or receiver performance, and it's reasonable to assume that anyone more
    than superficially involved in receiver or mixer design or application
    has at least heard the term. Or that they can at least do a simple
    google search. (It really doesn't take any more time than making an
    angry newgroup posting!) A google search of "IP3 mixers" brought about
    2500 hits. I'm sure that if you read one or two of them, you'll get the
    idea.

    Roy Lewallen, W7EL
     
  19. for 40m band even an SBL1 may be found inadequate and the solution is
    - as you say - a high-Q input selectivity using a 7040kHz ceramic
    filter which passes 7,0-7.1MHz within -6dB bandwidth.

    I've been told that my FT-902 with schottky ring mixer is worse than
    FT-901 with DG-mosfet 1st mixer, but I have no idea what is the main
    problem.
    I tested a mosfet mixer on 136kHz and found it adequate in most
    respects apart from IF leakage, and ended up with 74HC4066 mixer -
    used more for reason of being curious about it than that it was really
    needed, see http://home.online.no/~la8ak/L1.htm , but it couldn't be
    used on 60MHz as the orignal request was for, it might work on 40M
    with HEF4013 LO divider on +10VDC. Again you are fed with lot of crop
    from persons who don't understand the difference between what is
    optimum and what it the most expensive, so I expect somebody to telll
    me the nonsense of using FST3125 instead of 74HC4066 without
    understanding that the latter has almost 6dB higher IP3, and it is
    more fun to use an inexpensive device in spite of having the house
    filled up with lot of other better and expensive devices you won't
    have time to use in a lifetime.

    73 JM
     
  20. thought everybody had studied Ham Radio December 77 throughly - even
    in UK.....
    73 ex-G5BFV (at BPO radio station Bearley/SOA)
     
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