Help deciphering mod xfmr specs

[KM1H]

Ive had a Thermador CS-2156 on a shelf for ages and considering another project but the specs are confusing.

I understand the impedances but WTH does 48dB maximum mean?

Its also listed at 5000V Test. Is that AC peak/RMS or DC?

What is the audio power rating which is what Im trying to find out, it feels like maybe a 250-300W unit.

Anyone know what it came from? It comes up on Google several times with no info.

Carl
KM1H

[W9GT]

Ive had a Thermador CS-2156 on a shelf for ages and considering another project but the specs are confusing.

I understand the impedances but WTH does 48dB maximum mean?

Its also listed at 5000V Test. Is that AC peak/RMS or DC?

What is the audio power rating which is what Im trying to find out, it feels like maybe a 250-300W unit.

Anyone know what it came from? It comes up on Google several times with no info.

Carl
KM1H

I think that dB rating is a power rating.  Need a reference for dB,  Does it say dBm?

73,  Jack, W9GT

[W2XR]

Carl,

Probably +48 dBm power level, or 48 dB over a one milliwatt reference level. +50 dBm is equal to 100 watts when referenced to 0 dBm; 0 dBm is equal to 1 milliwatt.

That would equate to a power level of 60 watts if I am not mistaken.

Hope this helps!

73,

Bruce

[WA1GFZ]

how about dBM is 50 ohms right, so may be 48 dB above line level which I think is also 1 mw but into 600 ohms right?? Not sure how you deal with the Z but 60 watts sounds good.

[KE6DF]

To be a 300 W unit it should weigh around 25-35 lbs.

If it weighs that much, it's probably not a 60 watter.

I would guess a 60 watt transformer would weigh 10 lbs or less.

[KM1H]

I see all you guys are as confused as I am  This little thing weighs 53 # and has no cast iron end bells to skew the heft. It can handle some serious power.

Without a reference point that 48 dB marking (not dBm) has no meaning

Carl
KM1H

[k4kyv]

The reference level for 0 dB is normally 6 milliwatts.  0 dBm is, by definition, 1 milliwatt.

48 dB would come out to 384 watts:

30 dB = X1000

36 db = X4000

42 dB = X16000

48 dB = X 64000

64000 X .06 = 384

[KE6DF]

I have a Thermador mod transformer used in Wilcox transmitters. A picture is available here:

http://www.surplussales.com/Transformers/modulation.html

Mine was used for two 813's modulating a 250tl.

Rated about 350W.

But I don't think it weighs 53 lbs -- more like 30.

It's also an autotransformer.

There is a bigger version of it floating around which was used in a bigger Wilcox xmitter.

[KM1H]

Thanks Don, guess I should have opened Radiotrons Designer Handbook 4th Edition.....duh   I knew I was overlooking something in the relationships.

This iron is 8 1/4 W  x  6D  x 7 3/4 H

Primary is 6600. Full secondary is 4600 and tapped at 2300. Looks like it was used in 2 rigs. Response is 200-4000 cycles +/- 1 dB so that dates it as pretty old but looks new.

If this is rated at 384W there is no way the other of almost half the weight is 350W. Color is the same.

A couple of dead links on Google call it 500W.

Carl
KM1H

[KE6DF]

I took that Thermador transformer out and weighed it.

My guess was off. It's only 20 lbs.

That Surplus Sales ad  probably way overstates the power.

Besides, if it really put out 350W like the ad says, then it should modulated an input of about 700 watts which is more than the max CCS rating of a 250tl.

I'm betting they are using the rf input rating in the ad, and the transformer really puts out 1/2 that or about 175W.

I have another mod transformer, a Kenyon rated at 225 W that weighs 25 lbs and a 260 W UTC that weighs 35 lbs so a power of 175 W for my Thermador and 380+- for yours sounds plausible.

Yours sounds like a much bigger beast.