Sony ICF2001

[boiss]

Not really vintage, around 1980s.
Picked this up at the market this morning for 11 Euros, should have been 10 but the guy didn't have enough change. It's in quite good nick, no damage from battery leakage etc.Put 2 AAs for the computer, and connected a 5V supply. Very distorted sound apart from at low levels. AM/FM the same. Opened it up and did a few measurements as you do!!! Was surprised to find only -1.8V on the power line. Checked PSU 5V @400mA. Quick check on the specs and found that the 3 D cells only have a life of 10 Hrs. and that the normal mains supply 4.5V is rated between 9 and 16W consumption so this thing takes >1A +++. Tomorrow I'll go to a local market and try and find a 4.5V/5V 2-3 Amp supply. Has anyone any experience of these?
Hope this is the only problem!!!
Mike

[Joe]

There's some bumph here: http://www.radiomuseum.org/r/sony_icf_2001.html according to which the AC adaptor is only rated at 600mA.

- Joe

[Eddystonepete]

Careful with Sonys of this age, the power jack is often negative centre pin. Its usually marked on the case beside the jack. Many walkman pros have been damaged this way!
Peter

[boiss]

OK Guys,
thanks for the info and advice.
Found a charger at the market 5V 2A for 2Euros, Polarity wrong but cut and swap.
More volume less distortion but still the supply is being dragged down, it's about 3.8V. Hot sort of whiff, put a finger on one of the O/P trannies (gently) Wow!!!!!
Now I need some equivalents of 2SC1474 haven't got anything in my junk box that is small and can handle the current. Spec is 30Vc Ic 2A Hfe 150 NPN.
Cheers
Mike
I also picked up an Avo 8 for 20Euros. slightly damaged case. Hmmm

[Refugee]

It might be oscillating due to a bad SMD decoupling capacitor.
If it is not distorted at audio the transistors will be fine. Use a scope on the output to look for it.

[boiss]

Only 1 transistor was hot, the caps are all normal lead types. I know the SMD probs with the Sony Electrolytics as I have an ICF7600 and changed all the caps a couple of years ago. Before pulling the PCB out I will check it with a scope anyway.
Ta Mike

[boiss]

Transistors arrived today. Checked O/P with Scope nothing strange. (apart from distorted O/P) Removed Tr11 (visually cooked and S/C) removed Tr12 (measures OK) Replaced both with new 2SC1474s. Power on, all OK even the lamp works.
Incidentally there are no SMDs here unlike the 7600.
Mike

[tiv48]

excelent job i dont think i would of had nerve must be old age
rob t

[Joe]

Me neither, Rob. HT and live chassis bother me not at all but transistors scare me rigid.

- Joe

[boiss]

Gor Blimey, These trannys are quite big jobs as is the radio. A solder-sucker and a pair of long nose pliers and off you go!
Mike