COLLINS R - 390A / URR restoration. Συντήρηση δυο Ραδιοφωνικών Δεκτών Αμερικανικής Κατασκευής

Συντήρηση δυο Ραδιοφωνικών Δεκτών Αμερικανικής Κατασκευής. Η εταιρία Collins των ΗΠΑ είναι μια από τις καλύτερες. Ο Δέκτης αυτός είναι ένα απο τα ποιό επιτυχημένα μοντέλα . Θεωρείται ενα σημείο αναφοράς για όσους γνωρίζουν τα θέμα των Τηλεπικοινωνιών.

Πριν την συντήρηση κατάλαβα οτι χρειάζονται αλλαγη ή πρόσθεση κάποιων υλικών. Αυτα αναζητήθηκαν στο εξωτερικο και αγοράσθηκαν.  
Αγοράσθηκαν καινούργιοι πυκνωτές ειδικοί για τα μηχανηματα αυτα αφού παραγγέλθηκαν απο την Γερμανία.
Βρεθηκε το Relay μεταγωγής κεραίας και αγοράσθηκε μεταχειρισμένο καθως και τα βυσματα υποδοχων rf.
Αντικαταστάθηκαν στο ένα οι λυχνιες 26Z5W  με διόδους.

Throughout 28 years I am radio-amateur, i gained two used receivers Collins R-390A.
Used them during summer holidays at the wife's (sv7dna) born house,  900 Km south of our home. 
Its time to restore them .
The R-390A military shortwave radio receiver was the result of a project undertaken by the U.S.  army signal corp in 1954 to replace the existing R-390 receiver then in use. The R-390 had done its job so well that the Corps decided continued use of this type of receiver necessitated an improved, reduced-cost version.There are many references to the R390A in the open literature during this period; a picture of the receiver appeared in the May 1959 issue of the amateur radio magazine QST.
Total production of the R-390A (as determined by the high serial numbers noted) is over 55,000 units. Initial production started in 1955 and ran through approximately 1970, and then was restarted in 1984 by Fowler Industries for Avondale Shipyards. Manufacturers and their approximate production numbers are:
  • Collins Radio Company 6,363
  • Electronic Assistance Corp 15,338 (includes Dittmore Freimuth marked radios)
  • Capehart 4,242
  • Motorola 14,873
  • Stewart Warner 6,631
  • Amelco/Teledyne/Imperial 7,958 (these companies were related through acquisitions)
  • Fowler Industries 5
Companies which made spare modules, but not whole sets were Communications Systems Corp., Clavier Corp. and Hacking Labs.


The R-390A is a general coverage radio receiver capable of receiving AM, CW,  and  frequency shift keying signals. Its tuning range is from 500 Khz to 32 mhz, in 32 one-megahertz bands. The circuit is the superheterodyne type, double conversion above 8 MHz, below which triple conversion is used. It employs 26  vacuum tubes (6AK6 x 3, 5654 x 2, 12AU7/5814A x 2, 26Z5W x 2, 3TF7 x 1, 6BA6/5749W x 6, 6C4/6100 x 3, 6DC6 x 1, 0A2 x 1), a larger than normal count for most general-coverage receivers. The receiver weighs 85 pounds and can be operated on 120 volt or 240 volt supplies. It fits neatly into a 10.5 inch-tall standard 19 inch equipment rack.
Tuning of the R-390A's radio frequency and intermediate frequency front end is synchronized by means of an ingenious mechanical system of racks, gears, and cams. When the front panel tuning controls are rotated, this system raises and lowers ferrite slugs in and out of the receiver's tuning coils. This ensures that all front-end circuits are tracked, meaning all circuits are tuned to the correct frequency to maintain excellent selectivity and sensitivity. The receiver's construction is modular for easy servicing. Each major area of the receiver is contained in easily removable subassemblies, and these can be repaired or replaced as needs be. Though the R-390A is mechanically and electrically complex, alignment and servicing were designed to follow simplified procedures published by the Signal Corps.

Pictures - videos after Restoration                                    των δεκτών

 40 m reception

Am Reception

LSB Reception

εικόνες Μετα την συντήρηση:

Ο δέκτης εχει ακουστική έξοδο 600 Ω και γι αυτό στο Μεγάφωνο χρειάζεται μετασχηματιστής  Διαμορφώσεως

Receiver B




The tr switching missing
too grease

new tubes


 decided to ask friend's help . 

Είχα και άλλους κάτοικους που κάνανε χρήση των Δεκτών για κατοικία. Δουλεύανε και τότε πάντως..
βλέπετε οτι έχει μπει ένα καθαριστικό υγρό και έχει αφαιθεί για ώρες για να γίνει σε βάθος καθαρισμός

i found co-users of my Collins
wasp's nest

all out for relocation of units
dust grease and fluff

founded original t/r switch (not cheap)   before


Caps not good  needed Recaping
 new capacitors RECAPING (not cheap, came from Germany)



at the dryer  greek sun   / στον ελληνικό ήλιο για στέγνωμα/

to be continue
Ευχαριστώ τον κ. Ιωάννη Ιγγλλεζάκη για το ρελε και για όσα έκανε απο πλευράς του.