[Michael Deichmann]

I've just bought a Philco FT-9 121 autoradio - originally for Ford V8 1936, but I may use it in my European Ford Model C in stead.
It looks complete except I have no original speaker. I can't believe it should be a big deal to find one and buildin somewhere in the car. What impedance shouldit have? 8 Ohms? 4 Ohms? I believe speakers in the old days where more like 4 Ohms where they today are typically 8 Ohms.
Anything else to look after before I fire it up? I have a reliable 6V source like a lead acid battry, so no hazard there by using some powersupply or batterycharger :-)
Any advice are welcome!

[Eric Adams]

Hello Michael,
Welcome to the Phorum. First of all, do not fire it up. It appears from the photos that it has not been restored. All of the paper capacitors must be replaced. I don't know much about car radios but here is the schematic.
http://www.nostalgiaair.org/Resources/015/M0014015.htm

[Arran]

The speaker may have been mounted inside it's own box and mounted bellow the dash, in some it was mounted in the same cabinet as the radio chassis.
Regards
Arran

[Michael Deichmann]

Eric: OK - thanks. The picture shows the radio as found/bought. The link lead me to a better scan of the circuit and part list than I had before. So I'll have to swap all the caåacitors before trying anything. That will be on of the vacation projects this summer :-)

Arran: I have found some old brochures that shows that this version was for closed cars where the speaker was places just above the windshield in the lining under the roof (!). For open cars another version existed with build in speaker.

[Michael Deichmann]

I need some further guidance of something that are probably "kids stuff" to you radioarcheologists :-)

mfd = microfarad - I can guess that, but what is then mmfd? Micromicrofarads as I saw suggested on one webdictionary? Which equals nF (Nanofarad)?

[Eric Adams]

Michael,
Before you go any further, check this page: just radios

Then check this page: Philco knowledge base

[Steve Davis]

Mike, mmfd = pf

Steve

[Ron Ramirez]

Nanofarad (nF) is a unit of measuring capacitance that is generally not used in the USA, but is used in many other countries.

1 nF = 1000 pF (mmF or mmfd) = .001 uF (mF or mfd)

[bfrohwein]

I had to learn nf cause all my multimeter's love reporting anything under .1 mfd as nf. I used to use this cheat sheet until I trained my brain to automatically move the decimal point around.

http://www.justradios.com/uFnFpF.html

[Michael Deichmann]

Eric,
those links was just the information I was looking for. Thanks!

[Eric Adams]

I'm glad I was able to help.

[codefox1]

MF's usually need replacing, MMF's and NF's only sometimes. Vintage carbon resistors are always suspect for 101 reasons and best replaced for long time reliability, tubes only if needed. Cable and fittings to external antenna alwas suspect as well.

[Radioroslyn]

Hi Micheal
Welcome to the Phorum.
Basically your auto radio is the same as a table set with a few differences. The main difference is the power supply. It operates from 6volts DC at a fairly high current. I'd take a guess and say you'll need about 10-15amps of current to power is little puppy. This also means you'll need some large gauge wire for the power connections, maybe 10Ga or so. If you use wire that is too thin it will get warm and will cause a voltage drop.

The key part of the power supply is the vibrator. It's job is to chop up the 6VDC and turn it in to 6VAC. It's very important that the contacts inside are clean and smooth. Often they get pitted (very much like your distributor points) One reason for this is worn out buffer condensers in the power supply.They usually are connected the the contacts of the vibrator and have a very high volt rating like 2KV or so. Don't skimp on the volt rating as there are very hv spikes at that point and under rated one will short out. Once the power supply is working correctly you are on your way.

What I have done in the past to operate a 6V car radio for testing is to use a bench supply to provide heater and HV. 6VDC at a few amps and 180-220VDC for the HV To me it's easier and don't have to worry with the battery running low and voltage drop across the wiring.

As mention by others do replace all of the paper condenser and electrolytic ones too. The resistors due tend to change value over time so check them with an ohm meter. They where probably 20 percent jobs originally. If they still check within 20 percent your good if not time to change.

Have fun with it! Oh the other big difference between it and a table set is it can be a bit cramped and hard to get to some of the parts. Personally I don't like working on them because of that fact.

Would love to see a pic or two of the car it's going in to!
Best of luck with it and you have found a good source of technical help here. Lots of good smart folks that know much more than I
Terry

[Michael Deichmann]

Thanks Terry.

[wa2ise]

You can get solid state replacements for vibrators for car radios like yours at places like
http://www.tubesandmore.com/search/node/vibrator
They say to replace the buffer cap as well.