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Recent content by davidsrsb

  1. davidsrsb

    Sick of touchscreens in cars? Maybe good news is coming.

    I'm 6'3" as well, regular trouser inseam and a long body. I have my head striking the roof trouble with cars with sun roofs and many Asian cars.
  2. davidsrsb

    Diet ideas - what actually works?

    I'm down 4 kg so far this Ramadan. Missing the midday meal and trying not to over do the evening meal works and has improved my blood sugar.
  3. davidsrsb

    FM aerials. Talk to me

    Dipoles are directional, just like a single loop. Both have a very wide "beam" though. A loop has higher gain - I use a loop myself. The higher the gain of the antenna, the more directional it has to be - physics. This is one reason why there is a lot of debate about the Ron Smith models, as...
  4. davidsrsb

    FM aerials. Talk to me

    That table doesn't say dBd or dBi, which are 2.15 dB different, so I suspect dBi. My old 6 element can theoretically reach 8.5 dBd or 10.5 dBi. In practice 88 MHz to 108 MHz requires some detuning and a little loss of gain. Piling on extra elements, especially in a stacked way like the Ron...
  5. davidsrsb

    FM aerials. Talk to me

    I used to use a Tandy 6 element in the UK. There is little real evidence that the big Ron Smith designs really give much more gain. Nobody has ever shown any proper measurement or simulation. They do look impressive, though, but huge wind loading.
  6. davidsrsb

    Harrison Labs FMOD inline HP filters - opinions?

    The 909 is a little less. R2 22k in parallel with R5 62k and T1 input resistance, with C2 330n between them. R1 560R in series with the lot. So 22.5k at dc, rather less at audio, maybe effectively 15k?
  7. davidsrsb

    FM aerials. Talk to me

    The Quad tuners have normal sensitivities, not much worse than the best Japanese models.
  8. davidsrsb

    Harrison Labs FMOD inline HP filters - opinions?

    Why 20k? Remember that your load is usually anywhere between 10k and 100k, often 47k. This load is in parallel with your 20k. I would use a higher capacitance eg 220n or even 470n and work backwards.
  9. davidsrsb

    Why the world cannot afford the rich

    Even that needs qualifying with what the state of the country was before the revolution. Russia in 1917 was a shambles after being defeated by Germany. Charles 1 had a divine right obsession.
  10. davidsrsb

    "Filament" type LED bulbs fail much more than the other kind (?).

    Only a LED string with current set by series resistors is dimmable by a triac ontroller. The units with a smps try to maintain constant brightness over a wide supply voltage range. I have more exotic LED lighting where a remote control sets the smps current.
  11. davidsrsb

    Harrison Labs FMOD inline HP filters - opinions?

    A capacitor in series with the speaker is maybe better. I don't have info for the 988, the ESL-989 has a wild impedance that swings between 3 Ohms at 10 Hz and 25 Ohms at 100 Hz. A 150 uF bipolar or back to back 330uF is about right to give a steep cut at 70 Hz...
  12. davidsrsb

    Why the world cannot afford the rich

    The rich have an absolute obsession with making more. They are not normal and don't enjoy normal leisure activities - see Howard Hughes
  13. davidsrsb

    Harrison Labs FMOD inline HP filters - opinions?

    If the high pass is just a stacked RC, it is ultimately 12 dB/octave, but with a very gentle roll off. Putting two in series is going to not work well as the second filter will be driven by the high impedance of the first.
  14. davidsrsb

    "Filament" type LED bulbs fail much more than the other kind (?).

    Consistent. If a LED chip fails open, that string will go out completely
  15. davidsrsb

    "Filament" type LED bulbs fail much more than the other kind (?).

    The opaque ones have a smps in the base. It is this that fails, not the led array. Most of the time due to the output electrolytic capacitor failing - heat sensitive.


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