Hi all, I'm new to this forum and have come for some help. Don't worry, I plan to stick around. I am a mechanical engineer who likes working on cars and beginning to get into vintage audio.

I recently purchased a near mint looking Craig 1504 radio with the white and orange cone speakers. I saw one once at an estate sale and was admiring it when a old lady walked up, put a sticker on it, hollered i claim the radio and walked on. Since then I've had my eye out for another as it was too cool to pass up.

I bought mine about 4 weeks ago on eBay with the only known problem being the stereo light didn't work. I received it, and everything powered up fine and sounded good for about 3 weeks of garage jamming. This past weekend, while inside eating a quick dinner, the FM signal quit working and only static played. AM I am able to receive a faint signal from 1 or 2 AM stations but those are still fuzzy too. My external antenna or the internal antenna did not provide the fix.

Opening it up, the whole circuit inside looks really clean. I took pictures and can provide them later when i learn how to add them to this forum.

My questions are:
- Does anyone have a schematic for this board? Its a simple radio so I am sure the circuitry involved is probably pretty generic of other Craigs of the time or if they were owned by a parent company.
- Is the stereo light important to the circuit on these 60s/70s early circuit boards or a side voltage signal only? I believe they are important for the tube radios but uncertain as to why really.
- What common causes would a radio of this era have to lose all FM signal? I am assuming some cap popped. I did not see any smoke as I was not in the garage at the time.
- The circuit looks to be held into place via the 6 plastic chromed nobs pressed into the rotational pots. I think I have to pull them off the pots but pulled on most with as much force as I dared to pull and nothing budged. I am uncertain if that's what is needed to disassemble this unit. This is more of a 1504 specific issue.

Thanks for all the help. I have two other tube radios I want to get to in the future but this was purchased to listen to as is and not as a project. I want to get it done and enjoy the music, not the tinkering.

Thanks,
Andrew

Hello Andrew.

Shoot up some photos.
Posting photos to a forum thread...
The skinny: http://antiqueradios.com/forums/viewtop ... 0#p2717120

I cannot seem to locate any service information for your cube. Looks like Sanyo didn't have an equivalent model, so it probably was a bespoke product for Craig.

SOP is to replace all of the Electrolytic capacitors. But... you need to get the chassis on the bench.

Some tube radios have the dial-lamp as part of the tubes filament string (part of the circuit), maybe that's what you are thinking about.
All incandescent lamps (bulbs) have relatively short life spans.
Your radio will run fine without a lamp. Lol

1969 ad.


Welcome to the hood...
Greg.

Edit: Large images, front and back.
• https://ebth-com-production.imgix.net/2 ... uto=format
• https://ebth-com-production.imgix.net/2 ... uto=format

Here is a (Midland) generic of the era. Stereo bulb comes from transistor up, and to
the left.

However, three weeks jamming in the garage mighta snuffed
the output stage transistors in the 60 year old stereo. That
could draw down the overall voltage, causing the noise in
the speaker.

Gimmie that wrench set, here take this soldering iron....

Forget the 8 track.

Thanks for the schematic. Is there a place for this to be downloaded at full definition? I need to sift though it and highlight the Stereo circuit in it. I am unable to read the text and not smart enough to look at it and know what individual sections do my diagram alone.

I will work this weekend to see if I can safety remove the 6 turn dials from their pots without breaking them. if one breaks the value of this drops drastically, unless the knobs are generic and can be purchased. Until these are removed, I don't see how the board can be removed from the front face-plate.

I will take better pictures in the coming days and upload. I tried with my first post but nothing appeared.

This radio must be fairly rare, given the lack of info on it on the interwebs. Or it just is bad quality and no one purchased it when new. Maybe I can be compared to the Pacer, unique and cool (to some) but absolute rubbish.

One sold on ebay last month for $25.00

If you want help dismantling it, post some photos. Instructions above.
I have no idea what that schematic is. Lol

Greg.

I am that buyer! $50 dollars for a radio, I figured what the heck. It was supposed to be able to work...

I scanned that image from (Tab book 1026 ), 1978, edited by Mike Fair, titled Home Audio Systems.

I was in the service business in the 60s and Craig was a common brand.

If you cant find it on line, email me at ve7aso@rac.ca with your name and bricks and mortar
address, and I'll reply with the hi res scan. This board can only do 800 x 800.

Those sets were all about the same then. Budget stereos, easy to fix, sounded good,
and exceedingly annoying to the snoot nosed diamond stylus crowd.

Good news, I was able to get the board free of the faceplate. Bad news is, I really cannot see anything blatantly wrong. I spent a long time looking over it and no connections seem out of place. It was working for 2 weeks or so before it quit so something must have burnt up or shorted. I would have thought typically that would be visible.

More photos, the first was a tester. Apparently I take pictures upsidedown. They don't appear wrong on my computer so

Test points. LA1201 Sanyo Semiconductor. Part Number, LA1201. Description, FM / AM IF.

A start would be to measure voltages (carefully) on the parts mounted on the rear
aluminum panel.

By rear aluminum panel do you mean the thing at the RHS of the first pic? Or do you mean the rear panel covered by the rear particle board with cutouts for plug-in and speaker attachments? any specific voltages I am suppose to see? If the first option, what do those points represent?

Are the adjustable components resistors? Would those drift after extended use on one day after potentially sitting idle for a while? I don't know how much the previous owner used the radio.

Also there appears to be components that look like glass fuses or light bulbs. Are these either or also some form of resistor?

One note, that stereo light doesn't budge either. It's the top bulb built into the dial plate. I will give it another shot but its not worth too much hassle vs other projects.

Listen to the man. If this unit was built in 1969, it's components are 50 years old. We normally advise changing Electrolytic caps that are beyond 15-20 years of age. ALL of them.

I was not aware that some of these caps are Electrolytic? Which ones are? These are considerably different than my vintage Zenith I've worked on. I thought those caps looked new/modern.

Edit...
Nevermind, a quick google search shows that electrolytic caps appear to be all the bigger caps. I had assumed electrolytic caps were only those in the metal housings that have to be opened up and replaced individually.

One cap as seen in the pictures is a Rubycon 1000MFD 16WV. What units are WV? I can find 16V but uncertain if the W is a multiplier or some sort.

I will sort through a find replacements for each of the big gray ones. Do the smaller blue caps need replacing as well?

WV is short for working volts, 16V. is what its telling you the radio runs on.

All part of your learning process, lol. I believe 16 volts is the lowest value they make anymore for Electrolytics, so you should be good there on whatever you buy. ALL polarized caps, those with + and - symbols, need to be replaced. Here's one good source;
https://www.allelectronics.com/category ... ial/1.html

Replace all of these Electrolytic capacitors, including the Sanyo/Japanese plastic ones (shown below). They will have their values and polarity marked on them. Remove and replace them, one at a time.


Use capacitors rated at 35V or 50V (for 6.3V 10V 16V 35V) and 105°C temperature rating.
If the traces begin to lift, your iron is not hot enough - you want to get in-and-out quickly.

Modern day electrolytic capacitors have become so much smaller since the 1960's
Some of the old μF (microfard) values are no longer common... so choose the next nearest capacitance value, up or down.
... I buy the 50V ones today to replace the old 3V, 6V + 10V ones and 85°C is good enough for transistor radios.

It's foolish to hunt down 3V 6V or 7V caps.

As you do not have a schematic, mark their negative connection on the circuit board with a sharpie and... as I said earlier, replace them one at a time, otherwise you can get confused.

For my money, Panasonic... 105°C
FC series
FM series
FR series are all good capacitors.
------------

Before and after soldering...
I clean (and dry) with IPA (isopropyl alcohol) using a small acid brush or an old toothbrush. I use 70% (strength) isopropyl alcohol... mixed 50/50 with regular nail varnish remover (acetone), it leaves no residue.
In a past life I have used Zippo lighter fluid (naphtha) or denatured alcohol in a pinch.

More applicable to modern-day devices...
Adding lead solder to a lead-free soldered joint speeds up the removal process. It lowers the melting point.

If you haven't got a solder sucker...

.. EDSYN DS017 DELUXE SOLDAPULLT

...use fresh solder-wick. (The outer braid of TV coax can be used to soak up the old solder if you are in a jam).
Create a shopping-list and ask here if you need help.

Greg.


Edit: allelectronics and Digi-Key links here... viewtopic.php?p=2864980#p2864980

Thanks for all the tips! I have a large order to make now. This has considerable more caps than my tube radio.

I did have a question about a few though. I have about 5 little blue plastic covered caps that say "Sanyo 1/10". What size are these? Do they need replaced?

Also, that sea green "cap" pointed at in the upper corner says "Sanyo 25B187". Googling shows this as a transistor. It was difficult to see but I do see the three leads on this.

I wonder if the shear number of electrolytic caps, is what prevents people from collecting a restoring transistor radios?

Cant you explain the comment:
"If the traces begin to lift, your iron is not hot enough - you want to get in-and-out quickly."

I am not very knowledgeable about the specifics of soldering.

My bad, I thought it was a capacitor...
Good work Batman!

Post a photo of... "Sanyo 1/10"

------------

The ultra thin copper trace (pathway) that is bonded to the circuit board can come away if you goof around with it too much. Some radios are worse than others, take it as generic advice...

Most of your main board is wave soldered.



Greg.

Edit: Watch/save these soldering videos...
viewtopic.php?p=3030032#p3030032

Egg, within the photo you responded to last there is a little 1/10 cap hanging crooked on the edge of the board. It has a + & - side labeled. I will count them tonight and see if I can get a better pic of them. I will be in Cleveland for the rest of the week and will hopefully make my order while there. Anything else recommended while I combine shipping? I have all the heat shrink and clear plastic tubing for the old Zenith but by the boards design I wont really need it.

1μF (microfarad) 10V

Use a 1μF 50V as seen at the top of this page. UK store, for reference only.
https://www.bitsbox.co.uk/index.php?mai ... h=65_66_69

Greg.

When it comes to replacing them (one at a time), make doubly sure of their polarity/location as there is no schematic.

Edit: a selection of Today's common μF values can be seen here..
• https://www.bitsbox.co.uk/index.php?mai ... h=65_66_68
• https://www.bitsbox.co.uk/index.php?mai ... h=65_66_72
• https://www.bitsbox.co.uk/index.php?mai ... =65_66_356