marconi: 534;

hello all.

I need some help with some tube substitutions. I acquired an Marconi model 534 from Great Britan and I cannot find any North American substitutes for the British numbers.

can anyone help me on this?

the tube numbers are W42, X42, D41, H42 , N42 and U14

thank-you in advance, Ralph Besser

To thank the Author because you find the post helpful or well done.

Hello Ralph,

I am relatively certain that there were no "North American" substitute types, if you think along the lines of, say, 42, 80, 6A8 and the like.

However, there were equivalents and exchangable types from Cossor, Ever-Ready, Ferranti, Mullard, Mazda (Ediswan UK), Standard (Valve) and Six-Sixty.

You might have to try and acquire one of those or the original ones for your set. In the meantime, I can give you some information from the Mullard Catalog of Master Valves 1937. They say "it should be remembered that all types are not directly exchangeable". So this list is just a help and a start of investigation.

• X42 ≈ FC4
• D41 ≈ 2D4A
• N42 ≈ Pen4VA
• U14 ≈ DW4, DW4/500

The Cossor Valve Manual 1935-6 has the following "equivalents":

• U14 = 460BU

Unfortunately, their list of recommended tube substitutes for commercial receivers (including Marconiphone) does not yet include model 534 and I don't have a later edition.

r-type.org has an extensive list of equivalents. No warranty given of course.

• W42 = CV1183, NR61
• X42 = 15A2, CV3576, MX40, FC4, VHT4, 41MPG, A80A
• D41 = CV1170, CV1187, NR46, NR66
• H42 = none given
• N42 = KT42
• U12/14 = AU3, CV1064, CV1796, DW4-500, DW4/350, NU3, R4, UU120/350, VU64

Good luck!

Kind regards
Mark

To thank the Author because you find the post helpful or well done.

To complete the picture, I'll include the information from P. H. Brans Equivalent Radio Tubes Vade-Mecum (10th edition, 1953). It only lists replacement types, all of which but two have a different base.

• W42
  • 6R6G - A2, B1, D2-3
  • EF117 - A2, B1, C5, D2-3, E1-2
  • HP1118 - A2, B1, C5, D2-3, E1-2
  • RV12P2001 - - A2, B1, C2-5, D1-2-3, E1-2
  • W76 - B1
• X42
  • X63 - A2, B1
• D41
  • not listed
• H42
  • 6AD5G(T) - A2, B1
  • 6F5(G, GT, MG) - A2, B1
  • 6SF5(GT, GT/G) - A2, B1
  • 7B4 - A2, B1
  • 12F5GT - A2, B1
  • 12SF5(GT) - A2, B1
  • H63 - A2, B1
• N42
  • not listed
• U14
  • = 460BU

Explanation:

• A2 = different base
• B1 = different current and voltage
• C2 = different impedance
• C5 = different frequency limit
• D1 = different anode voltage
• D2 = different screen grid voltage
• D3 = different control-grid polarisation voltage
• E1 = different anode current
• E2 = different screen grid current

Regards,
Mark

To thank the Author because you find the post helpful or well done.