Recent content by chris vaudin

  1. chris vaudin

    RP10 Magnetic Flux Density

    Damn, I thought that I'd invented that demo with the top pan balance 30 years ago. I obviously wasn't the only one... Rather than use the single straight conductor (an aluminium rod in my case) I've just switched over to using Timstars F=BIL coil for top sets, concept is a little trickier but...
  2. chris vaudin

    What are you cleaning?

    We are wiping eyepieces with isopropanol on a lens tissue as this is pretty good on coated lenses. Only problem is that it's flammable, so let it dry completely before use. Don't forget to sanitize the focus knobs between users as well!
  3. chris vaudin

    Is it OK for lab techs to wear ties?

    Ahem, 1983 for me & still loving it. As for ties it's personal preference here, I don't but one of my colleagues does & is very concientious about tucking it in.
  4. chris vaudin

    Social distancing, what social distancing?

    Teachers & students (6th form) doing their desks, I'm doing the lab benches in between practicals.
  5. chris vaudin

    Mass Balance Protector

    Maybe give us a clue;) make and model of balance, size of cover etc. When you say "sticks on the balance plate" do you mean permanently or does it get removed before use? Do you have a DT department that could help you out with some sheet plastic?
  6. chris vaudin


    Hi folks, has anyone used "tastrak" plastic for detecting alpha particles? I think it's also called CR39. I used it once decades ago but the new HoD wants to try it out so I'm looking for experimental setups - how long to expose it for, best way to mount it etc. I've got the CLEAPSS details for...
  7. chris vaudin

    Strange Requests...

    Not a request as such, but a message on a technician e-mail group asking about electrolycra - a conducting fabric. I thought "why not just google it"? But doing that gives results mostly about electromagnetic shielding clothing to stop those nasty mobile phone signals from getting to you...
  8. chris vaudin

    No idea why it's taken me so long to join here!

    Hi, better late than never!
  9. chris vaudin

    I need cheap and reliable power packs.

    No formal qualifications but lots of on the job training, including safety, no live working on mains equipment and have been adjudged competent by our qualified electrician who also checks my work and performs PAT test on any repairs.
  10. chris vaudin


    Glad to help, we use these quite a bit, physics classes take measurements and calculate the wavelengths and Chemistry just come to see a few different spectra - it always surprises them that the blue/white mercury spectrum is made up of so few wavelengths whereas neon, which looks like it may be...
  11. chris vaudin


    Are these taken with the telescope directly in line with the collimator, ie images of the slit? If so they look fine. If you now rotate the telescope to one side or the other by 20 to 40 degrees you should see the spectra - for the daylight one I would expect a continuous spectrum from purple to...
  12. chris vaudin

    Wring diagram for leybold tube

    Looks like it's from an e/m tube, Leybold are a German company. magnetfeld will be the connections for the coils and Ablenkpl the connections for the electric field deflection plates. Leybold are still going so they may be able to help, or their British agents are Feedback Instruments Ltd.
  13. chris vaudin

    Is it broke

    That very back bit is just where the 6V heater for the cathode is, so it should glow rather than spark. Just double check your connections, 6Vac to the 2 sockets on the end of the cap and EHT (3 to 5kV DC) positive to the side connector. EHT negative depends on the age of your tube, on the old...
  14. chris vaudin

    Its all new to me!

    Hi ScienceDad, welcome to the madhouse! Glad you are settling in well, it should not take too long to train your teachers to do things your way;). There are lots of experienced technicians here so any problems, just ask away.