ERLA Model 4500 Dual-Wave T.R.F. 4-Tube A.C. Receiver
Radio Service Data Sheet
March 1935 Radio-Craft

January 1939 Radio-Craft [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Craft, published 1929 - 1953. All copyrights are hereby acknowledged.

I have been scanning and posting Radio Service Data Sheets like this one featuring the ERLA Model 4500, dual-wave, T.R.F., 4-tube, A.C. receiver for many years now. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. I usually attempt to find somewhere on the Internet of an actual existing example of the radios, but could not for the ERLA Model 4500.

ERLA Model 4500 Dual-Wave T.R.F. 4-Tube A.C. Receiver Radio Service Data Sheet

Band-Selector Switch: This receiver is de­signed for operation on two different frequency bands. The frequency ranges of these bands are : 1,720 to 540 kc., and 4,200 to 1,500 kc. Selection of the desired frequency band is made with the band-selector switch knob which is located on the lower right-front of the cabinet. When the band-selector switch is placed in the maximum left-hand position the receiver is operating on the 4,500 to 1,500 kc. band. For operation on the 1,720 to 540 kc. band place the band-selector switch knob in the maximum- right-hand position. To Align the Variable Condenser: It is important when aligning to follow the procedure carefully, otherwise the receiver will lack sensitivity and the dial calibration will be incorrect. (1) Connect the high output side of the oscillator to the receiver antenna lead and the ground to the chassis. (2) Place the band-selector switch for operation on the broadcast band; tune the re­ceiver to exactly 1,400 kc. on the dial and set the service oscillator frequency to 1,400 kc. Then bring in the 1,400 kc. signal to maximum output by adjusting the trimmer condensers located on top of the gang condensers. Note: Generally the rear gang condenser section trimmer bas to be adjusted to minimum capacity.

Posted February 2, 2017