I have found a good source of relatively cheap MSF time code receivers as part of the Sony Dream Machine, used from ebay. It comes in a small plastic box.
Several of these receivers did not work when they arrived. The cause in all cases was a SOT23 NPN transistor used as an RF pre-amplifier following the ferrite aerial. They have broken or cracked leads. In one case the transistor was completely missing with nubs of the leads showing in the original solder joints.

One of them was working and while testing it, I dropped it onto a carpeted floor and after that it did not work and the emitter lead was cracked.

For all of them replacing this transistor fixed them.

Has anyone else come across this kind of thing with SOT23 components?

 

How many leads does it have? The preamp prior to regnerative detectors is usually a dual gate MOSFET.

 

Considering that the receivers are probably assembled by an automated process, it is possible that the insertion machine is not adjusted perfectly. Correctly forming the leads is a rather demanding process, and getting it wrong is very easy. That is what I learned from hand assembling some small SMT prototypes one time.

 

How many leads does it have? The preamp prior to regnerative detectors is usually a dual gate MOSFET.

This component is definitely an NPN transistor.
It is not a regenerative receiver. I believe it is TRF with a crystal filter. It uses the U4224B chip https://www.farnell.com/datasheets/31773.pdf
It is intended for the 60kHz MSF time code transmissions from our National Physical Laboratory.

 

Considering that the receivers are probably assembled by an automated process, it is possible that the insertion machine is not adjusted perfectly. Correctly forming the leads is a rather demanding process, and getting it wrong is very easy. That is what I learned from hand assembling some small SMT prototypes one time.

The leads have broken between the soldered joint and the body of the transistor. The ends of the leads are still visible in the solder joint.

 

That is the area I was talking about. Incorrect lead forming produces cracks that break some time after soldering.

 

Can you bridge the break with some solder, or a tinned thin bare copper wire?

 

Can you bridge the break with some solder, or a tinned thin bare copper wire?

Yes, I probably could, but inspecting the result would be tricky as I can barely see the original crack.
It just seems to be a more reliable fix to replace the transistor.

 

Certainly a bit more reliable, but also more work and it costs more.
OF COURSE, that requires both adequate soldering equipment and adequate soldering skills.

 

Do you know the type of transistor you need?

 

Given that it a 60khz pre-amplifier I don't think it will be critical. I have been using BC818 (it's what I have) and that seems to work very well.