24-10-2017, 01:28 PM
I recently acquired this nice Roberts radio. On testing I discovered it was not working and had very heavy current consumption.
After getting a circuit I found that the problem was simply due to a short in the AC187.
I obtained a new AC187 and AC188 and after fitting consumption was as manual and it works well.
I set up R36 to 3.95v and R46 after cutting test link to 4.0ma and am pleased with results.
This is quite a nice little radio.
One thing I did before buying the new transistors was to test the RF parts were working by feeding C35 to a Hacker radio output board and this proved it worked.
The tuning capacitor was a bit noisy but this has sorted itself by use.
After getting a circuit I found that the problem was simply due to a short in the AC187.
I obtained a new AC187 and AC188 and after fitting consumption was as manual and it works well.
I set up R36 to 3.95v and R46 after cutting test link to 4.0ma and am pleased with results.
This is quite a nice little radio.
One thing I did before buying the new transistors was to test the RF parts were working by feeding C35 to a Hacker radio output board and this proved it worked.
The tuning capacitor was a bit noisy but this has sorted itself by use.
