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My 47-1230 Restoration

Very cool!  Thanks jcassity  Icon_smile

Rich

I "think" I found a problem today.  I got my tube tester.  It's a Jackson 115 and it turns out it's it's own project  lol.  It needs some cleaning and the glass in the meter is broken.  I took the meter out and took it apart and removed the broken glass.  I have some plexiglass that's 0.01" thicker than the glass, but I think it'll work.  I cleaned all the switches and controls and will work on cleaning up the front panel.

Anyway, the tester shows that 1/2 of the 7AF7 tube is completely bad.  If I'm interpreting the tube tester settings correctly it's the 1/2 that processes the radio signal.  The 1/2 that processes the phono signal tests ok.  It's hard to know if the tester is accurate, but I'll be ordering a replacement 7AF7 while I try to get the tube tester shaped up.

Rich

Hey jcassity - you've said a couple of times that your shortwave goes up to 15.5kc...but isn't it actually 15.5mc?  I'm just learning so may be wrong.  But when I do the alignment on mine it says to set the signal generator to 15mc.

Rich

sorry,, its MC.

and if you have 7AF7's double check your capacitor & resistor parts are correct for the application,, especially if any prior version had a 7F8 in ts place.

I noticed on my radio,,i am a code 125 but the parallel capacitor & resistor jumping around pins 2 & 7 were never updated.

Haven't done much on the Philco lately.  I did get new tubes.  I've replaced all but the 6V6 output tubes with NOS tubes and no real change.  I do get a little stronger signal with the new tubes on AM, but still no FM or SW.  I tried a 2 conductor long wire antenna with both wires tied together and connected to terminal 1 of the antenna strip, and nothing.  I might put this aside for a while and work on one of the other projects I have going.

One positive note though...I got my 3D printer and printed up a replacement for the missing bushing for mounting the pushbutton assembly:
   
The dimensions were a little off on this one so I had to adjust and print another one.

Rich

on mine, i found all my IF transformer ceramic caps were bottomed out.
this was not right. I did a quick read in the service document i got and it says to start adjusting each IF to max auidibility starting with the IF closest the the power supply and move your way out to the one closest to the antenna.

what i did was tune to am 960 which gave me at 70% volume gave me some degree of listening abiity and adjusted the first one closest to the power supply, i could hear an improvement once i went back and forth centering the cap upon the highest audibility. I did the same to the next and centered the cap to the hightest audibility ,, more volume started happening. the last IF transformer brought in more volume.

i concluded someone at some time in the past was preparing the radio for an alignment , i speculate that step one is to bottom out all the IF transformers then start injecting antenna signal.

doing what i did cured my humm noise and brought in more volume and more channels.

hope this helps

Quote:i concluded someone at some time in the past was preparing the radio for an alignment , i speculate that step one is to bottom out all the IF transformers then start injecting antenna signal. 


I bought a 16X one time that someone had tightened all those "loose" screws Icon_crazy

Steve

M R Radios   C M Tubes

Did they use a torque screwdriver on them? The one that clicks at 1lb-ft? Icon_smile

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.

i just followed the instructions and after the volume and hum was fixed, i stepped through the process to calibrate BC at the low and High end adjusting the two separate BC adjustments for alignment.  THere is only one SW alignment screw,, so far everything is close on the dial scale like within a 1/8'' , I used stations I knew where they were at such as instead of using 540 AM,, i used 610 because it came in well.  same for 1700AM.

i hope this is craigs issue.

Just to clarify...my name is Rich.  My Phorum id is criageek...looks similar to Craig, but isn't.  It stands for Cedar Rapids IA geek  ;)

Anyway, I've been through the alignment process many times.  I now have the AM working better but still not good enough.  I can have the volume on full and it would be listenable, but it's the level of output I would expect at half volume or less.  The high end of the band is much better than the low end.  The strongest local station is at 600 but it doesn't come in anywhere near as well as a couple of stations at 1360 and 1450, and even one on 1540 that's 50 miles away.  Mind you, this is with it sitting in my basement, but it should still get better reception than it does, especially on 600.

One thing that concerns me is that when doing the IF alignment, the cap on the last IF stage (which is the first to be adjusted) has very little effect.  It has to be turned completely out for best signal, but there it isn't much difference from when it's turned in.

Rich

Yes,,, on my chassis that was true as well,, the very first cap to be adjusted have little affect.
having it turned that far out is not what i experienced.

for the record,,, i cant get to the "center" adjusment on my "Last to be adjusted IF". The diagram shows two adjustments on this one if.

with all three of my IF's bottomed out..........
In order for me to be able to adjust the "FIRST" step one cap,, i had to cheat a little and go over to the "Last to be adjusted IF" and turn that cap a tad ccw to hear a faint something of a voice from a local station. I just rotated back and forth on this first to be adjusted cap for max audibility which at that point was still very low. Progressing to step 2 and step 3 worked out. again, on the last IF, i cant get to that center adjustment. something makes me want to mess with it again but it happens to be the IF that has one of its wires burried under my 7AF7 or whats probably your 7F8

I think i have two tubes you may be able to make use of,, i am going to look through this thread of yours to confirm.
I will never need them in my philco.

Thanks jcassity...I appreciate it!  But I've already bought NOS replacements for all my tubes except the 6V6 output tubes.

Rich

Hi Rich, I'm working on a 47 1230 also. am is ok and sw works well,but no fm. How did you make out with your's ?
Wink 

Hi willydcamaro!  I actually decided to set this radio aside for a while and work on some other simpler radios to gain some experience.  As you know the 47-1230 is not exactly a simple radio, and I had just started in the radio restoration hobby at the time so I decided I needed to do some learning before I really tried to troubleshoot the Philco.  In the meantime I have completed 6 radios, including one small transistor radio that my grandfather gave me when I was 7 or 8 (early 60s).
       
Along the way I've learned a great deal and have been thinking about diving back into the 47-1230.  But it'll probably have to wait a bit longer...right now I'm focusing on restoring the Seeburg AQ-160 jukebox I picked up in late December   Icon_biggrin

Good luck on your restoration!

Rich




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