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GeoffK · 28th Feb 2018, 1:40 pm

Hello Poppydog,

The switches should be checked first as these are quite complex and a fault in any one could stop the radio working, the ones common to all bands should be looked at as no bands are working.

Forget about the FM stage for now, on AM it is disconnected. Assuming AM IF is 470KHz

Take another working radio and tune it to a quiet spot on the MW band. Place the output of the signal generator near it and sweep the signal generator control past the 470KHz on the scale until you hear the tone in the radio, peak it so this is the 470KHz setting (band 4) on the signal generator. Turn the output level control to the minimum setting.

With a 0.01uF capacitor on the signal generator output probe and the internal MOD switched on and screen attached to the chassis, touch the probe against the cathode end (tap of L20) of the AM detector K5/2. Adjust the output for a minimum tone level with the volume control of the Akkord set to around half way, turn volume up and down to hear change in volume level, showing that the audio stage is working.

With the output of the signal generator set the same, and make sure it is the minimum that it can still be heard, put the capacitor probe on either C50 or C51 the base of second IF T4. The audio tone should get louder as T4 amplifies it.

Repeat by touching the probe to first IF T3 base C40, again the audio tone should get louder.

Finely put the probe against C22 and the audio should get slightly louder if T2 is amplifying.

If there is no amplification at any stage the transistor could be suspect or any of the components surround it. Other things to check is visually as it is all hand wired for any broken components or connections, and resistance checks of the various coils.

T2 the AM oscillator and FM first IF amplifier could be where the fault is if it is not oscillating on AM, but any of the small capacitors within the coil cans could be faulty, though these don’t often fail.

Make sure if you are supplying with a power supply that the current limit isn’t set to low, 500mA or so. Limiting the current to much can stop things working.
But the most likely culprit is one of the switch connections.

28th Feb 2018, 1:40 pm	#2
GeoffK Heptode Join Date: Mar 2016 Location: Essex, UK. Posts: 602	Re: Akkord Pinguin U60 Hello Poppydog, The switches should be checked first as these are quite complex and a fault in any one could stop the radio working, the ones common to all bands should be looked at as no bands are working. Forget about the FM stage for now, on AM it is disconnected. Assuming AM IF is 470KHz Take another working radio and tune it to a quiet spot on the MW band. Place the output of the signal generator near it and sweep the signal generator control past the 470KHz on the scale until you hear the tone in the radio, peak it so this is the 470KHz setting (band 4) on the signal generator. Turn the output level control to the minimum setting. With a 0.01uF capacitor on the signal generator output probe and the internal MOD switched on and screen attached to the chassis, touch the probe against the cathode end (tap of L20) of the AM detector K5/2. Adjust the output for a minimum tone level with the volume control of the Akkord set to around half way, turn volume up and down to hear change in volume level, showing that the audio stage is working. With the output of the signal generator set the same, and make sure it is the minimum that it can still be heard, put the capacitor probe on either C50 or C51 the base of second IF T4. The audio tone should get louder as T4 amplifies it. Repeat by touching the probe to first IF T3 base C40, again the audio tone should get louder. Finely put the probe against C22 and the audio should get slightly louder if T2 is amplifying. If there is no amplification at any stage the transistor could be suspect or any of the components surround it. Other things to check is visually as it is all hand wired for any broken components or connections, and resistance checks of the various coils. T2 the AM oscillator and FM first IF amplifier could be where the fault is if it is not oscillating on AM, but any of the small capacitors within the coil cans could be faulty, though these don’t often fail. Make sure if you are supplying with a power supply that the current limit isn’t set to low, 500mA or so. Limiting the current to much can stop things working. But the most likely culprit is one of the switch connections. __________________ *Geoff* Last edited by GeoffK; 28th Feb 2018 at 1:52 pm.