Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Philco Tropic 46-888 E.Z. Restoration
#13

The rest of the capacitors were restuffed and reinstalled. Any out of tolerance resistors not yet replaced were replaced. All of the original tubes that tested good were replaced, and any bad ones replaced.  A new power cord was attached.  I assumed that flat brown vinyl (likely originally rubber) is appropriate for 1946. I then carefully examined the chassis for unsoldered joints and solder blobs. I then checked once again for any B+ shorts. The speaker was plugged in, and an antenna wire attached. I pulled the rectifier tube and powered up the chassis using a Variac through a watt meter. I started at zero volts and gradually increased the line voltage while watching the watt meter. All the tubes lit up and current draw was normal.
 
I then reinstalled the rectifier tube and monitored B+ with my DVM.  I again powered up the chassis with my Variac through a watt meter while monitoring the B+. Power was increased at about 10 volt increments, allowing time for the new filter caps to reform. The band switch was set to the broadcast band and the volume control set a maximum.  At about 80 volts AC I heard some noise. I increased the AC to 115 volts. The radio actually worked on all bands. The volume control was smooth and free of noise.  The tone control, which was an area of concern, seemed to work OK although I’m sure not as well as it should, since the resistance had drifted from 6meg to 16megs! At maximum CCW, bass boost or loudness compensation was reduced.  As the control was rotated clockwise to about ½ rotation, bass increased. Further CW rotation reduced the treble.  So for most fidelity the control should be centered.  CCW rotation reduces the bass, and CW rotation reduces the treble. This seemed to agree with the schematic.
 
The next step is alignment of the two IF stages and 10 bands of trimmers! At this writing I have completed alignment of the IF stages and Shortwave #3 band. I was concerned about this band since my signal generator only goes up to about 12mHz with any stability. I have to use harmonics for adjusting anything above 12mHz. So to set the SW3 band to scale at 21mHz, I set the generator to 10.5mHz. I use a frequency counter to calibrate the generator. SW3 was easier than I thought it would be. Even the image frequency appeared where it should have been.  All that’s left is to complete the alignment, clean the cabinet, and reassemble.

Photos of the completed chassis are attached.


Attached Files Image(s)
           


Messages In This Thread
Philco Tropic 46-888 E.Z. Restoration - by davemc - 06-12-2016, 12:21 PM
RE: Philco Tropic 46-888 E.Z. Restoration - by davemc - 07-05-2016, 02:24 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Try looking at this site the book mark is for a old generator that I was given. David    https://radionerds.com/index.ph...David — 08:36 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Hello Everyone, I am looking for voltage identification for all the pin positions on the socket of a CRV-20130 power su...Tonym4704 — 08:16 PM
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM

[-]
Who's Online
There are currently 2022 online users. [Complete List]
» 1 Member(s) | 2021 Guest(s)
Avatar

>