SX-5530 FM just static

[QSilver]

I picked this up a while ago now online. It arrived and its been sitting on a shelf since then. I got it out today to take a look at and powered it up. Some panel bulbs are dead but its working ok, even with those nasty 726 transistors in it.

I went to try and pull in a station on FM... nothing. The tuning meter sits slightly to the left and neither it or the signal meter move at all. I tried to adjust the lower core of T5 to centre the tuning meter but it does not effect the meter so it is set back to where it was.

I tried AM and I do get stations on AM, sounding ok as far as AM goes.

I checked power and there is 13.5V going into the boards on Pin 20.

I checked around Q1 and Q2 for votlages and Q1 matches the schematic.

Q2 does not.

C: 13.5V
E: 0V
B: 0V

Does it look like Q2 is causing a problem or am I going at this the wrong way? I do have an FM generator, audio generator, scope and distortion analyser so hopefully I'm well equipped to fix it.

 

[QSilver]

Just a little update... I removed Q2 to test it with a transistor tester and my DMM. On the transistor tester, I got no hfe at all... and no readings through ECB with the DMM.... looks like Q2 is dead? Has anyone ever looked for a replacement for 2SC535?

 

[zebulon1]

I've been looking but have come up short so far. A guy on eBay has one with free shipping.
It looks like it's part of the local oscillator circuit so a correct replacement might be the way to go.
Nice set!

 

[rcs16]

2SC535 900MHz ft (ECB)
Use 2N5770 900MHz ft min (EBC)

 

[markthefixer]

2SC535 900MHz ft (ECB)
Use 2N5770 900MHz ft min (EBC)

I agree with Rick, Mouser has it, from Central semiconductor, Fairchild has obsoleted it.
610-2N5770 2n5770 ebc 15v 0.050a 0.625w 900mhz 20-200hfe

a princely $0.42 ea in singles, 10@ 0.302

 

[QSilver]

Thanks for the suggested replacement. I had a look around and found someone local selling their back stock of Fairchild 2N5770. I've ordered 5. When they get here I'll put one in, making sure to get the EBC correct, and see what happens...

It is a pretty good looking receiver. I like the light blue on the tuner dial... but I have a bit of a wobble on the tuning knob and the function switch has been bent too... but getting the tuner going is first!

 

[QSilver]

Transistors arrived today.. put one in and we've got FM! Carried out an alignment and its sounding pretty good now.

 

[zebulon1]

I love it!