Hammond or Triad?

[ALL212]

If using a choke is there a difference that should be noted that would determine which to use?

Triad C-7x vs. Hammond 158M.

Triad 90 DC m/a, 10 H, 270 ohm
Hammond 100 DC m/a, 10 H, 262 ohm

Hammonds are almost twice the price. 

[johnsonad]

In my limited experience, neither transformer measures anywhere close to the listed value in resistance. I've both and the build quality or at least finishing is better for the Hammonds.  I noticed no difference when used as intended.

[Chris65]

Triad is made in China, Hammond in Canada, which probably accounts for the price difference.
I also echo Aaron's comments.

[mcandmar]

I found the same as Johnsonad says when i had them side by side.  They are probably all made in China anyhow, as i found when i recently ordered a second Hammond power transformer.

[Chris65]

Hammond source some small power transformers from China (like yours), but as far as I'm aware all Audio transformers/chokes are still made in Canada.

[Paul Joppa]

I have not bought a C7-X in a long time, but they have been built in several places over the years. When the Paramour first came out, they were built in Mexico and done the old-fashioned way, layer wound with paper between each layer - this reduces the stray capacitance, improving high frequency performance as a plate choke. At some point they switched to regular bobbins, and (IIRC) later they were clearly made by Hammond without attribution.

The C7-X comes up often, because it is widely available. But since the layer winding was abandoned, I know of no special reason to stick with it over others with similar specs.

[ALL212]

I think in most cases we're replacing the 270 ohm 5w resistor.  How far off of 270 ohm can we be and still function according to spec?  These things are +- 20% IIRC.

[Paul Joppa]

It's not very sensitive. At 70mA, a 270 ohm resistance will drop 20vDC, which is much less than the usual 300-400v in a power supply. I would not even bother to calculate it as long as the resistance is between 150 and 400 ohms.

[ALL212]

Bought one of each for comparison:
Triad comes in at 245 ohm
Hammond at 188 ohm (measured 3 times to be sure)

Hammond packaging - very good.  Triad packaging, non-existant.
Triad has tinned ends, Hammond does not.
Triad reasonably close to advertised value.
Hammond...WTH??


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[mcandmar]

Hah my pessimistic prediction was true, they are made in China now 

Here are the two i have in stock,  Hammond 11.9H 192r, Triad 14.2H 244r

[ALL212]

For the Hammond it gets worse...

Triad 10.2 H
Hammond 5.3 H

I'm wondering now if I have a mislabeled choke from Hammond?

I'm going to return it - or try, and see what happens with the next one.

[Paul Joppa]

How are you measuring inductance? It is a function of the applied AC voltage, AC frequency, and  the DC current. You will usually get a small measurement if the applied AC voltage is small (<10v?) and/or the frequency is high (>120Hz).

[ALL212]

I've got an LCR meter.  I'm assuming it works ok.

[Paul Joppa]

That was my guess - these meters often use 1kHz tones at a fairly low voltage. Fine for air-core crossover coils, or for RF chokes, but not as relevant for power supply or plate-load inductors.

[ALL212]

Paul - does that mean I shouldn't trust it for measuring the chokes?  It appears close on the Triad but way off on the Hammond.