JimB was good enough to let me loose on the Philips 100 radio as discussed in length elsewhere.
In the first part I half stripped the chassis and got some music out of the front end of the set.
I needed to do that to test the tuning and IF coils and the health of the mixer and IF valve.
That was satisfactory so the next part will be rewinding the sad looking power transformer!


Fred.

Philips Model 100 Restoration - Part 1

Document uploaded.

I assume that ECB35 should be EBF35.

I'm surprised about that aerial wire. My 100A has a spring-loaded chassis-mounted metal terminal that looks original, rather than a random wire.

Hi Rob, they designed it so the set could be connected to the mains as a long wire antenna!
In a remote area that could be the difference between getting not much signal and getting something.
Ingenious and deadly.

This set does have the spring loaded terminal and that connects direct to the coil primary, point T1.
The two flying wires allow you to hook up the antenna configuration as shown on the sticker on the back of the chassis.
As the radio originally had a 2 wire mains lead, there was no earth connected to the chassis.
I will rebuild with a 3 wire mains lead, delete the two wires hanging out the back and the external aerial can connect to the spring loaded terminal.

The sticker will go.

Yep this chassis has the EBF35 with the odd heater pin connection and a ECH33 mixer.

Fred.

Yes those radios will need the longest antenna you can arrange, as they don't have much in the way of audio output, even at full volume - unless you live close to a transmitter.

A candidate for a reflex mod??

Hi Ian, might have a look at that.
My gut feeling is, as the HT is quite low the 6V6 is running very "soft" and will be part of the problem.
My set has the smaller PT and I now know why they went to a bigger stack, the small one is a stinker.
I have rewound it to the original specs and it has a large temperature rise with big voltage droop.
The 6V6 plate voltage will be around 180 volt if I am lucky.
I'll have to wait until get the whole thing running and see how it goes.
It really is a stripped design with 1 IFT only, uses a RFC on the mixer plate!
No AGC as well, could be fun.

Fred.

Well at least the RFC is tuned...

An idea instead of reflexing, given the 6v6 octal base. Replace it with a 6EM7. This is a dual triode that was used for 110 degree TV vertical deflection. Some early 60s AWA TVs used it.

The 2nd triode has a 10 watt plate dissipation but not unexpectedly has a low plate resistance of 750 ohms. So the speaker transformer primary will need to be changed to about 2k ohms. About 2 watts should be possible, depending on biassing and B+.

The gain of the two triodes (mu of 68 and 5.4 respectively) vs 9.8 for the 6V6 will give plenty of volume with enough gain to allow AGC to be added, at the expense of an extra cap and two resistors.

A far more civilised radio!

A search of the junk box might be needed, the 6EM7 has become a desirable audiophool valve and, when I just checked, is going for around $40! Or $35, including postage, on Ebay.

Ian, that is a thought!
Got some 6EM7 somewhere, could never figure out a use for them.
Can rewind a OPT to suit, easy.
This could be the "Hotting up the stock Philips 100" story!
Fred.