The Companion 249

Bulova Watch Corp.; Woodside (NY)

Dati
Forum
Immagini
Collezioni

  • Anno
  • 1955 ??
  • Categoria
  • Radio (o sintonizzatore del dopoguerra WW2)
  • Radiomuseum.org ID
  • 69035

 Specifiche tecniche

  • Numero di tubi
  • 4
  • Principio generale
  • Supereterodina (in generale); 1 Stadi BF
  • Gamme d'onda
  • Solo onde medie (OM).
  • Tensioni di funzionamento
  • Rete / Batterie (ogni tipo) / 117 / 2 x 1,5 & 1 x 67,5 Volt
  • Altoparlante
  • AP magnetodinamico (magnete permanente e bobina mobile)
  • Materiali
  • Pelle / stoffa / plastica ma con altro materiale sottostante
  • Radiomuseum.org
  • Modello: The Companion 249 - Bulova Watch Corp.; Woodside
  • Forma
  • Apparecchio portatile > 20 cm (senza la necessità di una rete)
  • Dimensioni (LxAxP)
  • 250 x 170 x 70 mm / 9.8 x 6.7 x 2.8 inch
  • Annotazioni

  • Leather case with strap.

    See the same radio with different colors: 246 and 247.

  • Fonte esterna dei dati
  • Volker Jeschkeit

 Collezioni | Musei | Letteratura

Collezioni

Il modello The Companion fa parte delle collezioni dei seguenti membri.

 Forum

Discussioni nel forum su questo modello: Bulova Watch Corp.;: The Companion 249

Argomenti: 1 | Articoli: 1

I recently restored a Bulova Companion radio chassis and leather case.  Presented below are my discoveries and experiences with this poor abused, now rescued, radio:

There is an Aerovox Resonant 0.1 uf resonant capacitor (resonalnt at 455Khz)  between circuit common and chassis.  I performed some tests to verify it's resonance and to better understand its function.  But to no avail.  It was eventually replaced with a UL rated Safety Cap of the same capacitance.  

With out the capacitor at all the radio experience "Birdies" all across the dial.  With the original Resonant Cap some birdies were experienced high on the tuning band.  See below test results:

> Line at 117vac; original selenium rectifier; 8 volts across filament string.
> No resonant cap - Birdies all over the band from 1620 to 530.
> Original Resonant cap back in - Birdies from 1620 to 1500
> New 0.1 uf Safety - Same birdies as Resonant cap.

 
> Replaced Selenium with Silicon and 180 ohm 2w resistor (tweaked for 6.20
volts across filament string (1.4v rated filaments all 4 tubes including the
3V4) at 120 vac) -
> Input AC Resultant
120vac  Same birdies as new 0.1uf non res.
117vac  One birdie at ~1600
109vac  No birdies at all.

 
> After alignment at 120 vac one birdie remained with very clear strong
reception.   Receives well at 117vac and Ok at 109 vac.
> Tweaked (moved) lead wires around oscillator coil and eliminated the last birdie!

 

It appears that the resonant Cap may have had another purpose.  One possibility is to filter out  Maritime wireless  location transmission and/or "Ship to Shore" radio phone operated at 455Khz.  This cap was used to shunt induced RF to ground. Other theories were tabled.  The full conversation may be viewed at http://antiqueradios.com/forums/Forum11/HTML/006043.html.  

The operation of the radio is quite acceptable and with out birdie once the new capacitor was installed, the rectifier replaced and the filament series string voltage adjusted with an added series resistor (just after the new 1N4004 silicon rectifier) to set the voltage at four (4) times 1.4 volts.  The 1.4 volts is the specified voltage for all four tubes in the radio.  The operation line voltage in my shop is ~117vac.  The isolation transformer was set to 120 for final testing of the restoration.

This text and pictures of the radio's origonal condition can be found on http://www.ppinyot.com/Bulova/bulova.htm

Also -

1) Is it possible to see a side picture, more detail of the strap, so that I may reproduce the strap for the unit I have? 

2)  Has anyone successfully restored the gold color embosed paint on this or a similar radio?  I want to try and restore the gold paint on this Bulova radio. 

All comments welcome.

Thanks,
Paul Pinyot.
paul[A*T]ppinyot.com

Paul E. Pinyot † 2013, 20.Aug.05

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