13-11-2026, 06:17 PM
I have had an interesting day restoring a Bush VHF 61 radio. I like these, they have their problems but are good performers. Whether it was a good idea to attempt this repair on Friday 13th is another matter!
First job getting the chassis out of the Bakelite cabinet. The speaker, tuning eye and ferrite aerial are on the speaker baffle, the speaker has spade connectors on the output transformer, the eye is held by a spring in a shallow recess and the ferrite rod held in grommets which slide out of the brackets, all very easy and considerate by the makers.
I wanted the baffle out for cleaning anyway, noting that the lower screws have extra washers hidden between the baffle and the Bakelite.
A quick check of the mains and output transformers with the ohm meter confirmed continuity. Checking the output valve grid capacitor showed significant leakage so it was replaced before applying any power. These sets unfortunately have lots of friable Hunts moulded capacitors which will have to be replaced but surprisingly none were broken, - so far.
Applying power with a lamp limiter proved there were no nasty shorts so full power was applied and reception on Medium and Long waves resulted but no FM. Not surprising really as there was no valve in the FM tuner!
Putting in an ECC95 produced very bad crackling and no FM reception, probably why the valve had been removed.
The tuning eye was totally dim as usual.
The source of the crackles was the FM tuner which is a cast aluminium enclosure held together with many 6BA nuts and bolts which unfortunately are fitted the wrong way round for easy removal of the front side so I had to remove the tuner completely. Not too difficult, two aerial connections above the chassis and five below.
The cord which pulls the coil slugs for the permeability tuning is wrapped around the AM tuning capacitor spindle and is difficult to access but with a bit of a fat finger fiddling it was disconnected without disturbing the main tuning cord.
I have had problems before with the two trimmer capacitors shorting in these tuners so once opened up these were checked and proved to be OK.
There are two anode feed resistors for the valve and these proved to be way out of spec, the 2.2K being very high and the 6.8K unusually low. Carbon resistors are know to break down occasionally, but its not common in my experience.
Finding nothing else likely to cause the crackles in there I replaced these as they were the most likely culprits, a fiddly job as I had to avoid moving components around too much as VHF tuners are fickle friends and can get oscillations when disturbed.
Fingers cross it was now OK, I reassembled and replaced the tuner in the chassis. Refitting the cord was fun but patience prevailed and it went back in the same position as it was originally.
Powering up produced good FM reception, thankfully. A success! Another fine set that will get completely restored,
An interesting fault I have not experienced before, very rewarding to fix.
Sam.
First job getting the chassis out of the Bakelite cabinet. The speaker, tuning eye and ferrite aerial are on the speaker baffle, the speaker has spade connectors on the output transformer, the eye is held by a spring in a shallow recess and the ferrite rod held in grommets which slide out of the brackets, all very easy and considerate by the makers.
I wanted the baffle out for cleaning anyway, noting that the lower screws have extra washers hidden between the baffle and the Bakelite.
A quick check of the mains and output transformers with the ohm meter confirmed continuity. Checking the output valve grid capacitor showed significant leakage so it was replaced before applying any power. These sets unfortunately have lots of friable Hunts moulded capacitors which will have to be replaced but surprisingly none were broken, - so far.
Applying power with a lamp limiter proved there were no nasty shorts so full power was applied and reception on Medium and Long waves resulted but no FM. Not surprising really as there was no valve in the FM tuner!
Putting in an ECC95 produced very bad crackling and no FM reception, probably why the valve had been removed.
The tuning eye was totally dim as usual.
The source of the crackles was the FM tuner which is a cast aluminium enclosure held together with many 6BA nuts and bolts which unfortunately are fitted the wrong way round for easy removal of the front side so I had to remove the tuner completely. Not too difficult, two aerial connections above the chassis and five below.
The cord which pulls the coil slugs for the permeability tuning is wrapped around the AM tuning capacitor spindle and is difficult to access but with a bit of a fat finger fiddling it was disconnected without disturbing the main tuning cord.
I have had problems before with the two trimmer capacitors shorting in these tuners so once opened up these were checked and proved to be OK.
There are two anode feed resistors for the valve and these proved to be way out of spec, the 2.2K being very high and the 6.8K unusually low. Carbon resistors are know to break down occasionally, but its not common in my experience.
Finding nothing else likely to cause the crackles in there I replaced these as they were the most likely culprits, a fiddly job as I had to avoid moving components around too much as VHF tuners are fickle friends and can get oscillations when disturbed.
Fingers cross it was now OK, I reassembled and replaced the tuner in the chassis. Refitting the cord was fun but patience prevailed and it went back in the same position as it was originally.
Powering up produced good FM reception, thankfully. A success! Another fine set that will get completely restored,
An interesting fault I have not experienced before, very rewarding to fix.
Sam.
Boater Sam.
