Great forum! Tons of useful information regardless of whether one is restoring Saba radios or not. I have learned a lot from reading this forum (with the help of Google translate, my German being just enough to ask for a beer and be polite). Hope my English is not too difficult to follow.
I am in the process of restoring this radio. This is not my first Saba, having restored a Meersburg 7 and Meersburg 6-3 (both automatics and the 6-3 included its remote control). Plus I have restored a bunch of other radios, including Telefunkens (Concertino 8 and 2194) and Grundigs (2066, 3028, 5040 3D).
The radio arrived in good condition without the usual deep dirt and nicotine that usually accumulates after 50 years. I have no idea if it worked or not as I did not turn it on until after I had removed and replaced all the paper capacitors and bridge rectifier.
Some one before me had worked on it as the dial strings for both AM and FM were completely wrong. I first corrected them, clean, greased, and oiled them for smooth and light operation. One problem remained, the FM dial would still slip. The clutch just did not have enough friction to drive the dial. This was solved by adding a small piece of kitchen paper towel (good thick stuff - like Bounty), cut to size into the FM side of the clutch. This dramatically increased the friction on the FM side and does not interfere with the AM side.
After changing the capacitors and rectifier I applied power and it all worked, or nearly so. All bands worked, but the automatic just barely moved. The problem was the 0.4uF motor capacitor. After changing this the speed was fine. Automatic tuning on the FM band works great. On the AM side, however, the search function finds stations with exceptional signal strength. I happen to live within 1 km of a MW station antenna. Search finds this and only this station, no others. I have readjusted the motor drive transformer, but no help as it was nearly perfect already. I then tried various tube substutions, with a small improvement it radio performance, but no real help in the motor drive. Continuing, I realigned the IF transformers. This again, helped with performance, but no improvement with the AM automatic tuning. Note: on the AM bands, once a station is acquired, the motor drive is staying on the station. I can feel the motor drive trying to keep it on station if I try to move the tuning dial with my hand. It is just the sensitivity for finding a station is too high. When realigning the IF transformers, I noticed that the adjustment for the primary side of the 1st IF transformer had no effect on the pass band curve. I plan to remove that transformer and open it to see if there is a problem perhaps with the capacitor.
I believe this radio has a delayed AGC, see circuit:
Does anyone know what the nominal voltage of the AGC should be without any station tuned in? At what voltage will the AGC become active? If anyone can shed any light on how the circuit functions, it would be appreciated.
Here are a couple of more photos:
I am in the process of restoring this radio. This is not my first Saba, having restored a Meersburg 7 and Meersburg 6-3 (both automatics and the 6-3 included its remote control). Plus I have restored a bunch of other radios, including Telefunkens (Concertino 8 and 2194) and Grundigs (2066, 3028, 5040 3D).
The radio arrived in good condition without the usual deep dirt and nicotine that usually accumulates after 50 years. I have no idea if it worked or not as I did not turn it on until after I had removed and replaced all the paper capacitors and bridge rectifier.
Some one before me had worked on it as the dial strings for both AM and FM were completely wrong. I first corrected them, clean, greased, and oiled them for smooth and light operation. One problem remained, the FM dial would still slip. The clutch just did not have enough friction to drive the dial. This was solved by adding a small piece of kitchen paper towel (good thick stuff - like Bounty), cut to size into the FM side of the clutch. This dramatically increased the friction on the FM side and does not interfere with the AM side.
After changing the capacitors and rectifier I applied power and it all worked, or nearly so. All bands worked, but the automatic just barely moved. The problem was the 0.4uF motor capacitor. After changing this the speed was fine. Automatic tuning on the FM band works great. On the AM side, however, the search function finds stations with exceptional signal strength. I happen to live within 1 km of a MW station antenna. Search finds this and only this station, no others. I have readjusted the motor drive transformer, but no help as it was nearly perfect already. I then tried various tube substutions, with a small improvement it radio performance, but no real help in the motor drive. Continuing, I realigned the IF transformers. This again, helped with performance, but no improvement with the AM automatic tuning. Note: on the AM bands, once a station is acquired, the motor drive is staying on the station. I can feel the motor drive trying to keep it on station if I try to move the tuning dial with my hand. It is just the sensitivity for finding a station is too high. When realigning the IF transformers, I noticed that the adjustment for the primary side of the 1st IF transformer had no effect on the pass band curve. I plan to remove that transformer and open it to see if there is a problem perhaps with the capacitor.
I believe this radio has a delayed AGC, see circuit:
Does anyone know what the nominal voltage of the AGC should be without any station tuned in? At what voltage will the AGC become active? If anyone can shed any light on how the circuit functions, it would be appreciated.
Here are a couple of more photos:
