Telrex trap?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KB0BRO, Jul 15, 2018.

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  1. W6LW

    W6LW Ham Member QRZ Page

     
  2. W6LW

    W6LW Ham Member QRZ Page

    Looks like a low power telrex 40 meter job. 100 watts. The high power had 2 ceramic doorknobs in series. Kilowatt AM. I still have a pair. I'm using one to auto decouple the top of an a latter line fed 100' apex 80m vertical loop into a bi square on 40m. Works excellent.
     
  3. W0FM

    W0FM XML Subscriber QRZ Page

    My first impression of the original photo was that it seemed similar to Telrex traps i had seen. But, unlike WIK, I didn't get the feeling that the trap was badly corroded, but rather, that, at some point during its lifetime, some one had glopped on a mess of marine hull sealant or roofing tar to extend its lifetime. Appears to be brushed on or applied with a paint stick.

    Terry, WØFM
     
  4. W9RAD

    W9RAD Ham Member QRZ Page

    Old post, I know. These traps were given to me by an OT and he told me they were Telrex.
    Dan W9RAD
    IMG_20200111_102642371.jpg
     
  5. W9GB

    W9GB Ham Member QRZ Page

    Telrex Traps used High-Q, High Voltage Ceramic Capacitors and Inductors (Wire Coil on form)
    Encapsulated in 7 coats of 3M Epoxy.

    2*pi*F= 1/sqrt(L*C)
    L-C Resonance Calculator
    https://www.daycounter.com/Calculators/LC-Resonance-Calculator.phtml

    High Energy Corporation (Parkesburg, PA)
    still manufacturers those classic High-Voltage Door-Knob Capacitors
    http://catalog.highenergycorp.com/category/ceramic-capacitors

    Telrex Catalog Pages (Asbury Park, New Jersey)
    http://www.hamradioweb.org/telrex.pdf

    Telrex “Balun-Fed” 40 and 80 meter “Duo-Band” Kit (1962, $48.00)
    Model DBBFD/48
    http://www.radiomanual.info/schemi/ACC_antenna/Telrex_DBBFD48_user_1962.pdf

    Antenna Traps (R—L—C)
    26647E65-EE89-4871-9602-DECF2336FE8B.jpeg

    Using Antenna Traps (Sotabeams, UK)
    https://www.sotabeams.co.uk/content/antenna-traps.pdf

    Jotrin Electronics (Russia)
    Antenna Trap calculator
    https://www.jotrin.ru/tool/details/TTXSJJSQ

    Typical Multi-band (40-20-15-10) Dipole Antenna
    B47C5710-701E-413E-AF58-01D433CA5D51.jpeg
     
    Last edited: Jan 12, 2020
  6. W9GB

    W9GB Ham Member QRZ Page

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