This is a complete battery portable radiogram from 1958, made by Hornython (owned by Philips) and featuring their portable turntable introduced to be an ad-on to radios or used in a motor vehicle. I was pleased to find this Austrian made unit in the UK and in amazingly good condition, above is the un-restored photograph. Buttons are labelled in German (I think) and basically are LW, MW, Tone & Off. The two wheels are volume and tuning. As per normal I added LED's to the dial. It uses 4 x 4.5 v batteries, 9v for HT and 9v for motor. A nice touch is a storage area that holds about 8 45's inside the back door with a protective card holder. It also has a socket for a car aerial to be plugged in. Late 50's cars had no radios but had a luggage rack by the passengers knees and radios could be rested on that.
the repair
Normal superhetrodyne circuit is used for radio, switching RF out with crystal audio in on the control switches. Quite advanced for it's day as transistors had only just arrived on the market. The record deck was a little stiff and needed some lubrication and switches cleaning. The original cartridge was fine until I had an accident and banged the needle damaging the crystal, shame really, but I found a similar one and fitted it fine.
Above show the main chassis, speaker (was loose) batteries, circuit board and 9 volt motor. Tiny amount of oil was added to the motor spindle and to most moving parts on the deck. When you insert a record it pushes a rod (see arrow) that moves the tone arm into the start position and while the record slides over the record spindle (drum) the spring loaded action holds it there, that in turn pushes the power to motor switch.
The contacts for the centre spindle switch will need to be cleaned, a little tricky to remove as lots of springs and washers to get access.
 |
Centre on-off switch for motor
|
With all mechanical units, lots of attention given to lubrication, don't go mad with application, just at the points of movement, I put a dab of oil on the end of a screwdriver to reach hard spots.
If the styli is missing the start of the record or dropping too far into the start a screw is provided to move the start point of the tone arm. (see arrow)
The end of the record is detected by a swing arm underneath and this uses the momentum of the spinning turntable to push out of the unit the 45 after play. If this is struggling, then clean the inside of the turntable where the rubber drive wheel locates.
I've added a video above to show the workings of the Hornython unit. The radio was working fine, loudspeaker was loose, but most of the work carried out was to the turntable, so lots of pictures have been added to help anyone else attempting to repair one.
No comments:
Post a Comment