Hi all,

I picked up a cream/salmon(?) Kriesler 11-99 valve radio for $35 today, but noticed that the power/volume knob is not original. I'm trying to track down a suitable replacement for it, since it's a nice little receiver in good (and working) condition.

http://www.radiomuseum.org/r/Kriesler_11_99.html.

Chris

Got a pic of one of the originals?

Edit, just saw the link, I've got brown with gold inserts.

The control knob for the power and volume is the same colour as the speaker grille on this model. Steve Savell is selling a lot of knobs on Ebay at the moment. He may have one for this model lying around somewhere.

Great little radios those 11-99's, they easily pull in the Sydney stations from the Blue Mountains without an external aerial. Something my 4 and 5 valve 1940's radios won't do even with a decent length of wire. The later production 11-99's had a silicon diode rectifier instead of a 6V4 which results in higher voltages. I've only got the circuit for the 6V4 version so I'm not sure what the correct voltages are although I've never tried to track down the right circuit (if it exists!). I've got a couple of them but unfortunately no spare knobs.

One would expect that there was a realisation of the extra voltage and either the transformer was changed, or resistance added in the B+, or B- rail?

Marc

I never really delved into it too deeply. The diode is a factory original with no signs of alteration, all other components match the schematic for the 6V4 chassis. B+ is about 25v higher than spec at 130v although they specify a 1000 ohm/volt meter so an accurate reading would be a few volts lower than this. The two 11-99's I've got are both identical with the same voltages, all caps replaced and all resistors either replaced or in spec. I always assumed that the change to a diode would eliminate the higher voltages at start up with a 6V4 and as such the valves were still operating within spec on the diode chassis.

It's possible that I have two radios with the same fault although they are great little performers with no sign of a problem. It'd be interesting if someones got the schematic for the diode chassis to see what voltages are listed.

The schematic for this one is glued inside the rear case, and although small, is somewhat readable. Was this standard for these radios?

When did production of these begin? The Radio Museum site has listed "1960?", which isn't very certain. Since there's a updated version with a silicon rectifier, I'm guessing this model ran for a few years?

Chris

When did production of these begin?

Nobody seems to know for certain -- even a guy who used to work for Kriesler at the time -- but circa 1961 is the usual answer.

The 11-99 was the last of Kriesler's valve radios and it was produced for a few years.

I've not encountered one with a silicon rectifier. When a valve rectifier is replaced by silicon, the HT is applied instantly instead of slowly as the rectifier valve heats up. In some circuits this can have ramifications for the other valves which get HT on them before their heaters have started to do their work.

I've read they were first produced in 1959 and ran until 1963. They were supposedly the last valve radio manufactured by Kriesler. Even though it's a factory diode the circuit in the back shows a 6V4 with the corresponding voltages. The serial numbers of my two are 27898 and 38406 so it seems they made a lot of them and quite a few with diodes.

Mine is serial number 17412. It has a blue ARTS&P sticker with AA prefix.

My radio has the serial number "189" written on the base and inside, and the dates "6 AUG 1965" and "30 JUL 1965" written on the IF cans. It doesn't have a ARTS&P sticker anywhere that I can see.

Chris

A Silicon Diode, or Metal rectifier will perform in a similar fashion to a filament rectifier like 80 / 5Y3.

This will create an initial surge that on a 250VDC under load rail can get close to 500V, which is why the caps had in many cases 525V surge (SV or PV) on them. Modern caps do not normally give surge volts.

This is why in most cases I will not use less than 500VDC caps on a non sleeved filament rectifier like 80.

The B+ is considered normal with a variance of +/- 20%
The loading of a 1000 opv meter on B+ is insignificant.

Marc

the dates "6 AUG 1965" and "30 JUL 1965" written on the IF cans.

We owned an 11-99 when I was a kid. Going by the house we were living in at the time it was new, it was bought in either 1965 or 1966. Certainly not before 1964.

Mention of 1963 as the production end year therefore had me scratching my head.

It's a shame there isn't a 'black book' showing the dates of manufacture of every radio between 1922 to the end of valve radio production. I guess the closest we have is the AORSM manuals though they weren't around in the 60s...

My schematic from JR is dated November 1961.