Dynatuner FM-1 Restoration

[denny9167]

I am in the process of restoring a Dynatuner FM-1 with the Multiplexing board for stereo operation,and I am going to re-tube it because I bought it without the tubes,and was wondering since the Magic Eye tube, that is required for calibration,is hard to find and expensive,is there a way to build a SS replacement for this tube,maybe using a couple of LED's or such,and other components to basically perform the same operation? Thanks in advanced.

[M Gregg]

Hi,

You haven't told us what the number of the "magic eye" tube is?

If it is as hard to find as you say why don't you just rewire the socket and use a different type?


Regards
M. Gregg

[Eli Duttman]

If it is as hard to find as you say why don't you just rewire the socket and use a different type?

That may be easier said than done. Look here for an article pertaining to the FM3, which is (more or less) a FM1 whose MPX is built in.

RES shows a $70 price for the EMM801. Whether or not they have stock is TBD.

[jfitz57]

Hi.

What are the tubes that you need? I've got tubes from a couple '60's stereos and one of them is a tuning eye tube.

[Gilgy]

Google says this unit uses an EM84 tube, ebay's teeming with them!

[Eli Duttman]

Gilgy is correct. Unlike the FM3, the FM1 uses a 6FG6/EM84 as the tuning eye. A PDF of the complete FM1 manual, including schematic, can be found here.

[denny9167]

Originally Posted by M Gregg

Hi,

You haven't told us what the number of the "magic eye" tube is?

If it is as hard to find as you say why don't you just rewire the socket and use a different type?


Regards
M. Gregg

I apologize, it is the EMM801,I have heard you could rewire it for use of the EM-84 tube,but does this yield accurate results?

[Eli Duttman]

Originally Posted by denny9167

I apologize, it is the EMM801,I have heard you could rewire it for use of the EM-84 tube,but does this yield accurate results?

The EMM801 has 2 sections, while the EM84 has only 1. Clearly, some functionality will be lost if an EM84 is installed. However, tuning accuracy is not impacted. Stereo indication is what you lose. Look here for instructions about replacing the EMM801 with an EM84.

BTW, if you are willing to replace the MPX adapter with something more modern, the attached circuit developed by MASTER DIYer Steve Bench will recover the stereo indication.

[jfitz57]

Originally Posted by Eli Duttman

BTW, if you are willing to replace the MPX adapter with something more modern, the attached circuit developed by MASTER DIYer Steve Bench will recover the stereo indication.

Hey! That's how I made my TV stereo! Only thing broadcast in stereo back then was some cartoon called Voltron or something like that.

[denny9167]

Her are a few picks of the progress,I will post as it moves along.