VFO/Buffer Unit? - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Skywave · 13th Aug 2009, 10:57 pm

Yes, Pat - I like the thinking.
Retain the original case-work & the mechanical bits . . and then fit replacement electronic innards according to the new freq range to be covered. In fact, I do recall doing such-like in my formative years in Amateur Radio! (Didn't we all?

).

That silver, cylindrical item. Is it the main VFO coil?

Al. / Skywave.

Nostaticatall · 14th Aug 2009, 4:42 pm

The aluminium can does contain the main coil. I've enclosed pictures of the unit in context with the rest of the TX. I said it was 813 based when I should have said 811 - I knew what I meant but the brain didn't (it does that a lot nowadays)! The empty ceramic octal base is for a 6L6 and the 'three in a row' octal bases are for series wired gas filled regulators.

I may dismantle the unit completely and do a proper Sherlock Holmes job on it one day but even then it probably won't unravel the mystery any further. As Al says, someone may come along and reveal all and spoil the intrigue but, until then, it will probably remain just a cobble together in a surplus box!

Steve

Skywave · 14th Aug 2009, 5:09 pm

O.K. - the main coil in the shiny can. I can't make out the lettering on it. Does it say "M B"?

Al.

Nostaticatall · 14th Aug 2009, 8:20 pm

Yes "M B" embossed in the lid. In between the initials are the symbols of a star and the female (circle with cross). Enlarged section enclosed although a little blurred.

Steve

Oldtimer74 · 14th Aug 2009, 9:37 pm

Having seen the overall picture I think my last guess was the best.
Pat G3IKR

Skywave · 19th Aug 2009, 12:50 am

Thanks for the reply, Steve.

I was hoping that the info. you have provided - "M B" - might reveal something formative on the 'Net - such as a manufacturer. Unfortunately, despite a detailed search, nothing has come to light.
So I regret to say that I've now 'run dry' on suggestions on this unit, fascinating as the search has been.

Al. / Skywave.

Nostaticatall · 19th Aug 2009, 9:38 am

Al - thanks for all the suggestions. It's probably going to have to remain a mystery although I have a feeling that one day I'll be reading an old PW or SW magazine and see a picture of whatever this used to be and all will be revealed - I won't hold my breath though!

I did wonder whether the coil can was also a red herring and possibly an early container used by May and Baker the pharmaceutical company and put into service here as a screening can.

I now realise that the crackle paint finish was done after the holes were made as there is some 'overpaint' around the holes. Also some small holes have been filled with solder on the front panel but not visible on the paint side again leading towards a later paint job. The problem I have with all of this though is that the lettering on the front panel is definitely professionally screen printed and not transfers. I've looked at it carefully under a magnifier to be certain. Whoever built it up from bits must have had access to screen printing facilities otherwise there is still a possibility that, in its unmodified form, it was as has been suggested, a prototype or experimental unit.

If I find the time, I'll strip the unit completely and identify what is and isn't original, down to the last nut and bolt - maybe that will help.

Steve

Skywave · 19th Aug 2009, 10:49 am

The problem with vintage things like this is that with the passage of time they get "tinkered around with" (that's as politely as I can put it!) and as a consequence lose key features that would otherwise help identify what it actually is. And of course, the more time passes, such tinkering - that would have been obvious at the time - often then becomes indistinguishable from the original build.
Again, what doesn't help is that amongst the thousands of items of such equipments that have been built over the period in question, there are bound to be obscure items that surface now & again - which could easily be from a very limited production run or even a one-off - for example, a specialised piece of test equipment that 'escaped' from a factory, has lain dormant for eons - and now mysteriously appears; electronic archaeology, for want of a name.

Recently, there was a similar Post that caused a good deal of similar head-scratching:

https://www.vintage-radio.net/forum/...ht=Mystery+Set

I realise that none of that exactly helps with your Q. - I say all that above simply by way of making a few personal concluding observations.

Al. / Skywave

13th Aug 2009, 10:57 pm	#21
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: VFO/Buffer Unit? Yes, Pat - I like the thinking. Retain the original case-work & the mechanical bits . . and then fit replacement electronic innards according to the new freq range to be covered. In fact, I do recall doing such-like in my formative years in Amateur Radio! (Didn't we all? ). That silver, cylindrical item. Is it the main VFO coil? Al. / Skywave.

14th Aug 2009, 4:42 pm	#22
Nostaticatall Tetrode Join Date: Jan 2006 Location: Preston, Lancashire, UK. Posts: 62	Re: VFO/Buffer Unit? The aluminium can does contain the main coil. I've enclosed pictures of the unit in context with the rest of the TX. I said it was 813 based when I should have said 811 - I knew what I meant but the brain didn't (it does that a lot nowadays)! The empty ceramic octal base is for a 6L6 and the 'three in a row' octal bases are for series wired gas filled regulators. I may dismantle the unit completely and do a proper Sherlock Holmes job on it one day but even then it probably won't unravel the mystery any further. As Al says, someone may come along and reveal all and spoil the intrigue but, until then, it will probably remain just a cobble together in a surplus box! Steve Attached Thumbnails

14th Aug 2009, 5:09 pm	#23
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: VFO/Buffer Unit? O.K. - the main coil in the shiny can. I can't make out the lettering on it. Does it say "M B"? Al.

14th Aug 2009, 8:20 pm	#24
Nostaticatall Tetrode Join Date: Jan 2006 Location: Preston, Lancashire, UK. Posts: 62	Re: VFO/Buffer Unit? Yes "M B" embossed in the lid. In between the initials are the symbols of a star and the female (circle with cross). Enlarged section enclosed although a little blurred. Steve Attached Thumbnails

14th Aug 2009, 9:37 pm	#25
Oldtimer74 Rest in Peace Join Date: Apr 2008 Location: Worcester, Worcestershire, UK. Posts: 330	Re: VFO/Buffer Unit? Having seen the overall picture I think my last guess was the best. Pat G3IKR

19th Aug 2009, 12:50 am	#26
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: VFO/Buffer Unit? Thanks for the reply, Steve. I was hoping that the info. you have provided - "M B" - might reveal something formative on the 'Net - such as a manufacturer. Unfortunately, despite a detailed search, nothing has come to light. So I regret to say that I've now 'run dry' on suggestions on this unit, fascinating as the search has been. Al. / Skywave.

19th Aug 2009, 9:38 am	#27
Nostaticatall Tetrode Join Date: Jan 2006 Location: Preston, Lancashire, UK. Posts: 62	Re: VFO/Buffer Unit? Al - thanks for all the suggestions. It's probably going to have to remain a mystery although I have a feeling that one day I'll be reading an old PW or SW magazine and see a picture of whatever this used to be and all will be revealed - I won't hold my breath though! I did wonder whether the coil can was also a red herring and possibly an early container used by May and Baker the pharmaceutical company and put into service here as a screening can. I now realise that the crackle paint finish was done after the holes were made as there is some 'overpaint' around the holes. Also some small holes have been filled with solder on the front panel but not visible on the paint side again leading towards a later paint job. The problem I have with all of this though is that the lettering on the front panel is definitely professionally screen printed and not transfers. I've looked at it carefully under a magnifier to be certain. Whoever built it up from bits must have had access to screen printing facilities otherwise there is still a possibility that, in its unmodified form, it was as has been suggested, a prototype or experimental unit. If I find the time, I'll strip the unit completely and identify what is and isn't original, down to the last nut and bolt - maybe that will help. Steve

19th Aug 2009, 10:49 am	#28
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: VFO/Buffer Unit? The problem with vintage things like this is that with the passage of time they get "tinkered around with" (that's as politely as I can put it!) and as a consequence lose key features that would otherwise help identify what it actually is. And of course, the more time passes, such tinkering - that would have been obvious at the time - often then becomes indistinguishable from the original build. Again, what doesn't help is that amongst the thousands of items of such equipments that have been built over the period in question, there are bound to be obscure items that surface now & again - which could easily be from a very limited production run or even a one-off - for example, a specialised piece of test equipment that 'escaped' from a factory, has lain dormant for eons - and now mysteriously appears; electronic archaeology, for want of a name. Recently, there was a similar Post that caused a good deal of similar head-scratching: https://www.vintage-radio.net/forum/...ht=Mystery+Set I realise that none of that exactly helps with your Q. - I say all that above simply by way of making a few personal concluding observations. Al. / Skywave