Mariner Auto-TRG Pilot Mariner MkII

Brownlee Brothers Limited; Dublin

  • Year
  • 1954 ?
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • ID
  • 162294

 Technical Specifications

  • Number of Tubes
  • 6
  • Main principle
  • Superheterodyne (common)
  • Wave bands
  • Broadcast, Long Wave and Short Wave.
  • Details
  • Record Player (perh.Changer)
  • Power type and voltage
  • Alternating Current supply (AC) / 220 - 240 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) - elliptical / Ø 8 inch = 20.3 cm
  • Material
  • Wooden case
  • from
  • Model: Mariner Auto-TRG Pilot Mariner MkII - Brownlee Brothers Limited;
  • Shape
  • Tablemodel, with any shape - general.
  • Notes
  • There is also a Radio version.

    This is adapted from case and based on the metal work of the  chassis of the UK Pilot Blue Peter, but location of smoothing capacitors swapped with audio transformer and valve bases changed from Octal & Loctal to similar B7G and B9A types. One band less. The fourth RF trimmer position is not connected, unlike the Radio version. Another difference is the ferrite rod with MW, LW and aerial matching coils. The end aerial coil is slightly adjustable.

    Despite the label showing a 12AH8, one sample appears to to be factory wired for the ECH81. They are not interchangeable without changing heater connections, also the 12AH8 has the Triode grid internally connected to the Hexode g3 to allow the centre tap on the 12.6V heater.

    It's not at all similar to the UK version of Pilot Mariner.

    The Trawler band is omitted. The 6BW6 is actually similar to the 6V6.

    The tone  and gram are combined as three presets for radio (Bass, Music, Voice) and two presets for gram (Normal, Bass).

    The Magic Eye is the Octal varient of the 6U5.

    An external aerial isn't required. The chassis is isolated via the mains transformer, unlike many Pilot UK models of the period. This is one of a range of models adapted for the Irish market and assembled in Dublin. The UK Pilot 85 series, particularly the T85M, is a similar circuit.

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Forum contributions about this model: Brownlee Brothers: Mariner Auto-TRG Pilot Mariner MkII

Threads: 2 | Posts: 4

Undoubtedly at some stage Brownlee (or Pilot) changed from using the 12AH8 to the widely available ECH81. There is no evidence that the chassis was ever wired for the 12AH8.

The Pilot Mariner Mk II Radiogram chassis mainly differs from the radio only table model in having a ferrite rod and only one RF section coil on the chassis rather than three. This variation is also on the Trader sheet 1126 Pilot 85 series, though it uses two frame aerial coils.

The other difference is a third coil (2.2mH in air, 3mH on the rod) right on the very end of the ferrite rod connected across the aerial and earth terminals via chassis wiring. A slim coax cable also connects to this point to connnect to an aerial in the cabinet.

The IF appears to be 471 kHz, same as the UK Pilot  754, 85A and 85U. The T85M (R&TVS) is listed as 470 kHz.

ECH81 cathode: 2.2V, 220 Ohms, 47 K from triode grid to cathode.

6BA6 cathode: 0.75V, 62 Ohms.

The 6AT6 has feedback from the audio transformer secondary, like the Pilot "Blue Peter", with 33 Ohms cathode to chassis and 220 Ohms from speaker secondary. Only 15mV. The grid leak is 10M Ohms. 10nF connects the anode to the 6BW6 grid. A 270 pF mica capacitor on the anode decouples IF. Tone control (Bass, Music, Voice) is  possibly via feedback. The same switch is used for normal and Bass Gram input.

The 6BW6 output differs from the Blue Peter and 85 series. The audio transformer has a tapped primary which feeds 2K (or possibly 2.5K, the paint was burnt off) to the dual 32uF HT capacitor. The centre tap is fed from the 1st 32uF and the 6X4 rectiier.  Due to the feedback and type of audio transformer there is no "Tone Correction" / Snubber capacitor on the primary or 6BW6 anode. The cathode is 8.2V using a 270 Ohms decoupled with 25uF 25V rating.

6X4 HT: 253V DC (with 230V AC mains).

HT1 after 1st dropper fed from audio transformer: 180V. This feeds most ot the set. There is a 2K dropper at the 6BA6 decoupled with 100nF giving 82V.

Six paper dielelectric capacitors were replaced. Perhaps a couple not so  critical:
2nF, 5nF, 10nF and 3 x 100nF.

The blank magic eye was replaced with a Russian NOS 6E5C (6e5s). One link is required for the target HT. There is a series 1M  Ohm from AGC line to the eye grid, presumably to stop space charge affectiing the AGC voltage? The AGC from the final IF is decoupled by 1 M Ohms and 100nF. The feed to the switch selecting radio or gram to the 500K volume control uses a curious combination 47 K (IF stopper) and capacitor (less than 1nF?) that looks like a tubular ceramic capacitor with an extra leg at one end.

There is a thermistor on a tag of the transformer to chassis, use unknown. No obvious voltage selection.

Michael Watterson, 14.Jul.19

Weitere Posts (3) zu diesem Thema.

this particular model , in possession of maitiu standun , year of manufacture 1954, made under lisence in ireland , the turn table fitted is not the correct version, it should have a gerrard turntable ,regards etc , maitiu

Maitiu Standun, 10.Oct.09

Weitere Posts (1) zu diesem Thema.