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John Caswell · 6th Aug 2020, 12:38 pm

Always fancied one of these, and managed to pick one up for £40 plus external PSU and audio amp, with the film scale in a can and the workshop manual.
Externally a bit shabby but internally almost like new.
Refitting the film scale looked a bit daunting as the set requires a fair amount of dismantling, but with the book, pretty easy. Usual problem of solidified grease and oxidised oils, all cleaned up and lubricated using moly based grease and modern oils.
Needed to be quite dexterous really, with ideally 3 hands to do the scale but managed pretty well at third attempt, and refitted it correctly as per book.
Reassembled the unit powered it up and set the film scale centrally to the cursor at 2.5 MHz injected 2.5MHz and it was pretty close, reasoned that the alignment hadn't been touched so adjusted the flexible coupler to match scale to frequency.
Tried on all other bands and very close, so a quick twice of alignment probably called for after 60 years.
Whilst on the bench I managed to knock the RF amp valve and the signal dropped in level. Tapping around the signal varied in level accordingly. Looking at construction I thought Oh *** need to take the RF unit our again. Not so, someone had put a lot of thought into the construction, as all screening panels were easily removable (excluding myriads of screws). Once panels were removed and the unit powered up, it was easy to trace the problem which was a non-soldered joint on the RF valve base cathode connections. Re-soldered it powered it up and bounced/dropped the unit around the bench - perfect. How this joint had survived over 60 years I don't know as the exterior, as I said, looked knocked about a bit
Left it running all day - minimal drift uncased so reasoned all good.
Now to make a proper PSU for it, might be able to fit it inside the case after taking out all the vibrator PSU bits and pieces, we shall see.
A beautifully made unit, easily serviceable - you can see why military equipment costs so much.
A pleasing couple of days work the satisfying results.

John

6th Aug 2020, 12:38 pm	#1
John Caswell Hexode Join Date: Jul 2009 Location: Wokingham, Berkshire, UK. Posts: 437	R210 Larkspur receiver Always fancied one of these, and managed to pick one up for £40 plus external PSU and audio amp, with the film scale in a can and the workshop manual. Externally a bit shabby but internally almost like new. Refitting the film scale looked a bit daunting as the set requires a fair amount of dismantling, but with the book, pretty easy. Usual problem of solidified grease and oxidised oils, all cleaned up and lubricated using moly based grease and modern oils. Needed to be quite dexterous really, with ideally 3 hands to do the scale but managed pretty well at third attempt, and refitted it correctly as per book. Reassembled the unit powered it up and set the film scale centrally to the cursor at 2.5 MHz injected 2.5MHz and it was pretty close, reasoned that the alignment hadn't been touched so adjusted the flexible coupler to match scale to frequency. Tried on all other bands and very close, so a quick twice of alignment probably called for after 60 years. Whilst on the bench I managed to knock the RF amp valve and the signal dropped in level. Tapping around the signal varied in level accordingly. Looking at construction I thought Oh *** need to take the RF unit our again. Not so, someone had put a lot of thought into the construction, as all screening panels were easily removable (excluding myriads of screws). Once panels were removed and the unit powered up, it was easy to trace the problem which was a non-soldered joint on the RF valve base cathode connections. Re-soldered it powered it up and bounced/dropped the unit around the bench - perfect. How this joint had survived over 60 years I don't know as the exterior, as I said, looked knocked about a bit Left it running all day - minimal drift uncased so reasoned all good. Now to make a proper PSU for it, might be able to fit it inside the case after taking out all the vibrator PSU bits and pieces, we shall see. A beautifully made unit, easily serviceable - you can see why military equipment costs so much. A pleasing couple of days work the satisfying results. John