Ekco AC74 Restoration

I've just finished the repair work to an Ekco AC74 that I recently purchased. The set was in very nice, original, untouched condition. I read the service data right through from the BVWS CD ROM and I was intrigued by the dial cords carrying the current to the dial bulbs so that only the bulb for the waveband in use is lit.

When I got the set ready for restoration the first difficult task was to remove the control knobs, however with some WD40 and a small screw driver they eventually came off without any damage.

The speaker lead had to be unplugged and the chassis withdrawn. On the base of the chassis a plate was secured by 2 screws which completely encloses the chassis. This had to be removed and then access to the entire chassis was possible.

The first job was to change every condenser in the set and fit a new mains lead. All windings were then checked with a test meter and found to be intact.

The next job was to clean all contacts, there is a wave change switch with about 10 contacts, these all had to be cleaned as did the volume potentiometer and the valve holders and bases. There is also a sprung earth contact on the cursor used to light the dial which also needed cleaning to avoid a bad contact and consequently interference.

Once this was all done everything was double checked and the set reassembled and powered up. Long Wave was quite sensative but medium wave was dead. On further investigation it was found that one of the switch contacts was not making properly. The contacts were cleaned further and given a good spray with Servisol, this really did the trick. The set was then powered up again.

Both wavebands now worked but there was some distortion. The set has a LOCAL/DISTANT switch so this was tried but the distortion was present on all stations.

From the circuit diagram I read that the speaker grill could be removed from the front of the set by twisting in an anti-clockwise direction. This took some persuasion as I did not want to break the Bakelite. It came out without any damage and was greased to make future removal easier. The centre of the speaker cone was adjusted by a small turn on the nut in the centre of the speaker. This did the trick, the sound quality was then perfect - loud, clear, good tone and highly sensitive.

The only other job that I had to do was to tighten up one of the drive cords for the dial as one had become very loose and kept slipping. This was done where the cord meets the spring, and solved the last problem. I don't know what exactly the drive cords are made from but they are obviously conductive. Thankfully they were not broken as I imagine it would be hard to obtain a replacement.

All in all it was a very enjoyable restoration project, a very well made set and a joy to use. The fun part then came with finding somewhere to put it, that was a very enjoyable task and it now has found a home in the front room. A very stylish set from 1933. All in all the restoration work was pretty straightforward, the main thing to just double check on would probably be the wave change switch and the illuminated cursor arrangement.

-oOo-

One small problem which did develop after the restoration was finished was that the set would occasionally fade away either partially or completely. After replacement of the SP4 valve the set has been fine ever since.

[oh2gtk]

For conductive lines one could use very thing steel wire or fishing line with steel cover. I have found out that when it comes to cords - it is actually fishing equipment stores that have it. Fish - Radio - Fish - Radio ... they do sound very similar, don't they