Tuning problem on RCA 46x11 after recapping- HELP!

Another Happy Camper, now you can hear the broadcast band a Short Wa(V) a way!

That's great. I'm glad you got it. By the way, when the local oscillator quits in a superheterodyne receiver the set will go dead quiet-no output at all. That is one of the symptoms to watch for. Good on the new signal generator. I have a couple of them here. I mostly use the newer solid state model as it doesn't need any warm up before use. It is a B&K Precision 2005A clone.

So I found the problem, I thought I had been thorough in my testing but I missed the continuity on terminal 2-3 and 1-2 on L5  oscillator so I repaired the broken #2 wire and it makes sense with no signal the AGC could not give as much audio as shortwave and also no tuning to be done.  I bought a rf signal generator all the same and will use it to align the radio now that it works.  I bought a refurbished BK precision 2050.  Thanks for all the helpful suggestions and it looks like this one is solved !!

Hi Rod, very nice info and I will try these items and get back to the forum to report results.   I am again receiving shortwave from Huntsville, Al to Nashville Tennessee on the built in antenna with the link in place.  When I switch to AM I get less sound and definitely no tuning white noise.  I did get the schematic and service manual but lack the knowledge and equipment.   I will try to hook on the oscillator stage with the voltmeter and resistor as I don't have another receiver.  The oscillator coil was very crunchy during adjustment and has smoothed somewhat.  I can hear the difference if I change the oscillator coil while it is playing shortwave. The bandswitch looks like clean tracks but I will try to gently clean and tighten with a small screwdriver.

First of all, I am assuming that you have access to service info on this radio from Riders or N.M. Beitman manuals if not an actual RCA Victor service manual (they are out there). Any of these would come with a schematic diagram and alignment information. I get my service info on older radios from Nostalgia Air online resources. They have scanned in all the Riders manuals. 

There are a number of areas at the front end of the receiver that could be causing the Broadcast Band to be inoperative. Since the Short Wave band is functioning you can rule out the 12SA7 converter tube itself as faulty as well as the 12SK7 IF stage and the IF transformers and all the stages that follow.

From the schematic diagram and alignment info I can only say that this is a (2) band radio covering the medium wave Broadcast Band (AM) and one Short Wave band. I checked to see if it has a phono input jack but I didn't see one. The antenna input terminals need a closer look on this radio. There is a link to close on the antenna terminals if you are going to use the internal loop antenna only. You might check on that. More to the point on an inoperative band is to check if the oscillator stage is functioning. You check for that by seeing if you can pick up the oscillator stage signal on another receiver. The oscillator should tune from about 990 kHz to 2055 kHz on the Broadcast Band for an older radio with a 455 kHz IF frequency. 

Another way to check to see that the oscillator stage is indeed oscillating is to use a high input impedance voltmeter and measure right at the control grid G1 (pin 5) of the oscillator stage to see if there is a least a few volts negative present. This indicates oscillation. If you don't have such a meter, insert a 5 Meg Ohm resistor in series with the negative lead of your DMM and use this as a probe to check for the voltage. Ground the positive lead of you meter to B- which appears to be the chassis ground on this radio. You can reverse the test leads connections if you like in which case the meter will show the voltage as being negative if any is present. By the way, you should be using an isolation transformer when you work on any AC/DC set like this.  

If you have picked up the oscillator signal on another radio then you know the oscillator stage is functioning. If not then you need to focus on that area of the set such as checking the oscillator coil and possibly substitute another coil for it. A replacement coil will be way out of tune at first and will require a careful adjustment to get it to where it needs to be (aligned) to bring in stations at the proper points on the dial. Another point to check is the bandswitch. They can give a lot of trouble if there is any corrosion present on the various contacts-enough to make the set inoperative. Spray cleaners may not be able to remove this corrosion. In some cases it has to be scrapped off carefully with a small screwdriver. If the oscillator stage is functioning there could still be a problem between the antenna coil, the bandswitch and the connections to the converter stage's signal grid #G3, pin 8.

As far as doing the RF alignment part goes, lacking a signal generator, you could hunt for (2) broadcast stations in your area at around 600 kHz and 1400 kHZ to use as signals to do the required alignment at the low end and the upper end of the Broadcast Band.

Gotta go for now. Hope this gives you something to go on.

Hi all, I hope to avoid questions like "have I used a meter before" etc by saying I have recapped and restored over 200 amps, receivers and guitar amps. I have a multimeter, oscilloscope and dim bulb tester among my tools.  I am new to aligning radios however and my neighbor asked me to repair his dads 1940 rca 46x11. 

To start I replaced all resistors, electrolytic and film capacitors with the values listed on the schematic and put a .05 mfd y2 safety cap on the line to ground. I also tested and put NOS value tubes in all positions.  I have a calibrated Hickock rd 1575.  I had to substitute a 20 watt 790 ohm resistor at pins 1/2 on the ballast resistor socket and bridge to 3 as this tube was shot.  I cleaned all the controls with deoxit and rotated them many times.   It turns on and I was listening to shortwave last night as I did not have any luck with tuning AM with or without and external antenna properly installed.  

So I have a few questions, first what are the positions for the three bands?  Shortwave came in on the clockwise most position.  Next how would I go about getting AM to tune without a rf signal generator to align it or is it possible?  If this does not seem possible is there someone in my area that could perform this for a modest fee ?  I am in the Huntsville, AL area

Please be kind to the newbie, I am just trying to do a favor for my neighbor as his dad passed away and this would make him happy.

Cheers and Thank you for reading my post

Scott