Got a new multimeter

Discussion in 'General Electronics Chat' started by tom66, Feb 12, 2011.

  1. tom66

    Thread Starter Senior Member

    May 9, 2009
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    First, a little rant: This meter was $99 + $35 shipping, which was a pretty good deal. That made it around £85. But because I ordered it from the USA (couldn't find it *anywhere* in the UK) I had to pay £23 in customs fees / VAT. :( That made it a bit more expensive than I had originally intended.

    But, it is a nice meter. It's a BK Precision 2709B. True RMS, 6,600 counts, 0.5% basic DC accuracy. Very good protection; two massive MOVs according to internal pictures, along with HRC fuses. Continuity mode is fast (<100ms) and latched (which is very good.) Most other ranges autorange very quickly. Capacitance is a bit slow, but does go up to 66mF, and it does let you range switch through it. It measures frequency, up to 66 MHz(!), which eliminates my need to buy a separate frequency counter, for now at least, as long as I don't need to measure very high frequencies.

    It's also got input jack detection. If you select a voltage range, but plug the probes into the current jacks, it beeps at you to alert you to this (very useful!) All ranges but AC/DC volts are protected to 500V; AC/DC goes to 750Vrms/1000V.

    I chose it mainly because Dave Jones (eevblog) highly recommended it.
     
  2. someonesdad

    Senior Member

    Jul 7, 2009
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    On B&K's website, there's a link "Where to Buy" and they give a UK distributor:

    Company: Metrix Electronics Ltd
    City: Hampshire
    Country: United Kingdom
    Phone: 44 845 0343234

    If that one isn't current, an email or phone call to B&K might have uncovered another distributor near you.
     
    Last edited: Feb 12, 2011
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    Bk..I never heard of 'em..
     
  4. tom66

    Thread Starter Senior Member

    May 9, 2009
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    Dammit, if I'd known that... anyway, I've bought it now.
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    The frequency bandwidth is impressive! Price isn't too bad either.

    What is the shortest duration will the min/max/avg function catch? 1mS 10mS?
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    Just some recollections....
    One of B&K Precision's early products was a TV picture tube rejuvenator. I remember reading about those things back in the 60's. The basic idea was to get the cathode really hot by increasing the heater voltage temporarily, and then giving the cathode a HV blast that would strip a layer of the cathode material off. This was far better than methods that were offered by other manufacturers.

    I remember a "picture tube brightener" which you plugged in between the chassis harness and the picture tube base; my Dad bought one in the early 60's for our big DuMont black & white TV that was getting dark. I'm sure what it contained was a transformer to boost the voltage supplied to the heater filaments, increasing the emissions from the cathode.

    In those days, when you turned off a TV, the picture shrunk to an eerie white dot that remained for a long time in the center of the screen, which I would watch with fascination; I had no clue that I was being exposed to X-ray radiation. More modern CRT TV's had circuitry to prevent such emissions. Nowadays, you can't even buy a CRT TV, they are all LCD or LED panels.
     
  7. tom66

    Thread Starter Senior Member

    May 9, 2009
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    I believe it is limited to the sample rate, so only 333ms (3 Hz sampling.)

    I also know now how I missed that supplier - I went to BK's site, typed in "2709B" to search for distributors, and got this list:

    http://www.bkprecision.com/where_to_buy/index.php?invt_id=2709b&match_opt=S&wtb_ref=UNKN

    The closest one was Sefram, but they had no pricing. All the others were US based.

    SgtWookie, your story brings an interesting point; why do modern CRT TVs flash when you turn them off? I remember once having a TV which did not do this. It was a sales point, I think, but I don't really know why...

    To test the frequency counter, I can use my dsPIC33F which should be clocked at 36.85 MHz +/-1%, or my PIC24F, clocked at 14.7456 MHz +/-0.005%.
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    Can't tell you offhand.
     
  9. marshallf3

    Well-Known Member

    Jul 26, 2010
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    Hard to beat a good B&K
     
  10. debe

    Well-Known Member

    Sep 21, 2010
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    Hi wookie, I still have one of those picture tube brighteners. Here in Australia they were made by Arlec, was a small 240V to taped outputs of 6.3/7.5/8.5/9.5V ac @ 1Amp. they certainly extended a BW picture tube, then that was back in the 60s.
     
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