[R-390] Dittmore&Freimuth mechanical filter

[Les Locklear]

Heinz and Group,

Dittmore Freimuth Corp. Made their own mechanical filters. The Collins patent had expired.

The Helena Rubenstein Filters would be marked Collins.

Les Locklear
Gulfport, Ms.
DX'ing Since '57








  ----- Original Message ----- 
  From: Heinz Breuer DH2FA 
  To: R-390 List 
  Sent: Saturday, February 12, 2011 6:37 AM
  Subject: [R-390] Dittmore&Freimuth mechanical filter


  Hello,

  a friend's jukebox revealed a R390A style mechanical filter with markings:

  Dittmore&Freimuth
  SM-D-243863
  S/N:013
  No: DF-455-BP-2-CB

  I have not yet tested it but I guess it is a 2kc filter. Did 
  Dittmore&Freimuth make their own mechanical filters or is it a Collins 
  OEM product?

  vy 73 Heinz DH2FA, KM5VT

  PS: I am looking for a Helena Rubinstein filter? hihi

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