25-06-2013, 09:44 AM
Thanks for the many replies and ideas
I should clarify the word 'pot' - it is actually a mult-turn dial (not the original) that drives a slow motion drive (again I don't thinks its original) which ultimately moves an arm a long a coil.
I believe the 2 units involved were originally from a commercial / military receiver. These unit were incorporated into a 'home brew' setup which was ultimately pulled apart and left to gather dust for 40 years. Unit 1 is the tuner etc and unit 2 is the power supply and AF amplifier. Both seem to have been modified/repaired. I seem to remember having some info/circuit somewhere - see if I can hunt it down.
It is continuous tuning (although it overlaps at 110mhz). The multi-turn dial has at least 20/30 turns from top to bottom
To listen - I am running the 21.4 IF output into a Racal RA17L (tuned to 21.4mhz).
I am guessing that probably the original receiver may have had a 2nd if and filters and obviously a detector. The next project!
I did say that I would prefer an analogue meter to display frequency - but I am open to a mechanical dial or further ideas ( I guess that is why I posted). But obviously an idea of frequency would be good (and meter came to mind) - also this should prevent damage to the delicate tuning coil upper and lower mechanical limits.
I am not trying to return this to its original state (whatever that may have been). This receiver is probably circa 1950s/60s , modified/repaired, and pulled apart during the 1960's (brought back to the UK from Ascension island 1968), rebuilt in some fashion during the 70's, and once again pulled apart, finally receiving a new AF output transformer, and a couple of capacitors circa June 2013. Its had a bit of a journey of the last 5/6 decades. Returning it to an authentic state would in my opinion eradicate part of its history. I quite like the idea of vintage mixing with modern.
If interested I will try to provide photos of these units
Thanks again for your ideas and help
Regards Paul
I should clarify the word 'pot' - it is actually a mult-turn dial (not the original) that drives a slow motion drive (again I don't thinks its original) which ultimately moves an arm a long a coil.
I believe the 2 units involved were originally from a commercial / military receiver. These unit were incorporated into a 'home brew' setup which was ultimately pulled apart and left to gather dust for 40 years. Unit 1 is the tuner etc and unit 2 is the power supply and AF amplifier. Both seem to have been modified/repaired. I seem to remember having some info/circuit somewhere - see if I can hunt it down.
It is continuous tuning (although it overlaps at 110mhz). The multi-turn dial has at least 20/30 turns from top to bottom
To listen - I am running the 21.4 IF output into a Racal RA17L (tuned to 21.4mhz).
I am guessing that probably the original receiver may have had a 2nd if and filters and obviously a detector. The next project!
I did say that I would prefer an analogue meter to display frequency - but I am open to a mechanical dial or further ideas ( I guess that is why I posted). But obviously an idea of frequency would be good (and meter came to mind) - also this should prevent damage to the delicate tuning coil upper and lower mechanical limits.
I am not trying to return this to its original state (whatever that may have been). This receiver is probably circa 1950s/60s , modified/repaired, and pulled apart during the 1960's (brought back to the UK from Ascension island 1968), rebuilt in some fashion during the 70's, and once again pulled apart, finally receiving a new AF output transformer, and a couple of capacitors circa June 2013. Its had a bit of a journey of the last 5/6 decades. Returning it to an authentic state would in my opinion eradicate part of its history. I quite like the idea of vintage mixing with modern.
If interested I will try to provide photos of these units
Thanks again for your ideas and help
Regards Paul
