[dconant]

Hello, I found a schematic here but I would like the service manual that would have the parts list and locations as well as alignment instructions. Can someone help me out with that? I found another one on Tom Bavis's site but the alignment instructions are not there.

I just recently picked this radio up and it appears to have all original tubes (globes with Philco paper label) and they test very good. The cabinet needs a lot of veneer work. Looks like it got wet. The speaker is frozen. I will do a separate post for that.

It will a while before I get to this radio. Looking forward to it though.

Thank you,
Dan

[RodB]

Try this link:
https://philcoradio.com/library/index.ph...ers-vol-1/

Pages 6 through 9 and 21.

[dconant]

Thank you Rob. Hopefully that will work when I get that far.

Dan

[dconant]

Hello, I have begun the restoration of my Philco 91. I have been looking over the parts and the very first one I checked is way off. It is a 160K resistor connected to pin 4 of the 44 (RF) tube. It looks factory. That resistor does not exist on any of the schematics I have for that radio. The schematic shows connection from pin 4 of the RF tube to pin 4 of the IF tube with nothing in between. The other end of the resistor connects to block 9. Also the connection between pin 4 of the RF and IF is through a switch. This switch is on the same post as the on/off switch. It will be the bottom switch in the picture.

Schematic here https://philcoradio.com/library/index.ph...chematics/ in the 1932 section. My chassis is code 121 based on the label attached to the metal tube shield. 

I found a schematic on Nostalgia Air showing the switch as being a frequency switch. There is only one band on the radio. The NA schematic is for code 126-226. The schematic is here http://www.nostalgiaair.org/pagesbymodel...013884.pdf. Off to a crazy start already.

Thank you,
Dan

[RodB]

Hi Dan,

I can't explain this specific resistor but I have seen the use of a switch to apply B+ voltage to screen grids of rf tubes to give a boost in gain to pull in distant stations. The switch was called a range or local/distance switch. Does the resistor connect to the ground terminal of block 9? It may be there to reference the grids to ground when the B+ is switched off. That would make the tubes run as triodes.

[dconant]

Hi Rod,

The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of the switch, from the other side of the switch to block 9 and then to pin 4 of the IF tube. It seems to me the resistor is in parallel with the wire. With the switch off the resistor is in circuit and when off it is not. So with the switch in one position the two pin 4 connections are directly connected and the other way they connect through the resistor. If what you say is correct then where is the B+ coming from? I just realized pin 4 of the RF tube connects to block 27. Parts list says this is a .01 cap but the block has two caps or one cap and resistor in there as all three connection points used. I don't find another 27 on the schematic.