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crestavega · 5th Sep 2017, 12:17 am

How can I find a pinout for this old cylindrical "tin can" package of a MC1496 balanced modulator?

I am starting to think there might be a problem associated with the Motorola MC1496 Balanced Mixer in me T128 Tx....

on reflection this seems unlikely because it is pretty much the beating heart of the whole Tx, and the Tx is almost working - just low in power.
I am clutching at straws a bit, but I have arrived at this deduction by following the "Typical Voltages & Waveforms" chart in the manual (p50 of the T128 PDF at peel.dk)

TP14 was low at around 0.8V (should be 4 - 5V)
TP13 was correspondingly low at 0.7V (should be 3 - 4.5V)
TP12 was OK at 0.6V
TP11 was OK at 0.7-1V

TP11 & 12 are inputs to the MC1496 whilst TP13 is the output which goes to the driver.

was using a 50MHz CRT scope for the measurements.
I feel that I ought to check the power supply for the MC1496 but Im not too sure how without a pinout...

5th Sep 2017, 12:17 am	#56
crestavega Pentode Join Date: Apr 2014 Location: Kirkwall, Orkney, UK. Posts: 165	Re: Sailor T128 Marine Transmitter. How can I find a pinout for this old cylindrical "tin can" package of a MC1496 balanced modulator? I am starting to think there might be a problem associated with the Motorola MC1496 Balanced Mixer in me T128 Tx.... on reflection this seems unlikely because it is pretty much the beating heart of the whole Tx, and the Tx is almost working - just low in power. I am clutching at straws a bit, but I have arrived at this deduction by following the "Typical Voltages & Waveforms" chart in the manual (p50 of the T128 PDF at peel.dk) TP14 was low at around 0.8V (should be 4 - 5V) TP13 was correspondingly low at 0.7V (should be 3 - 4.5V) TP12 was OK at 0.6V TP11 was OK at 0.7-1V TP11 & 12 are inputs to the MC1496 whilst TP13 is the output which goes to the driver. was using a 50MHz CRT scope for the measurements. I feel that I ought to check the power supply for the MC1496 but Im not too sure how without a pinout...