RE: "Buddhafying" the FM-3

Posted by strijw426 (A) on May 16, 2011 at 19:28:47

In Reply to: RE: Ceramic IF Filters and Tube Type Tuners posted by Eli Duttman on May 13, 2011 at 18:43:08:

Eli;

Thanks again for this information. I downloaded the two articles and read them. I looked up the data on the 6AQ8 and the 6DJ8 in two tube manuals I have. The 6AQ8 is described as a "high-mu dual triode" and the 6DJ8 is described as a "medium mu dual triode". Internal electrode capacitances are quite similar. However the 6DJ8 is a later design and the transconductance figures shown in the charts in the back of the later RCA tube manual show that the 6DJ8 produces almost twice the gain of the 6AQ8. From statements made in the articles the 6DJ8 also has a lower noise figure than the 6AQ8, so it is better in two ways.

The changes required to use the 6DJ8 in the FM-3 are relatively easy to do and I might give that a try. My FM-3 still works well and still has original tubes except for just one that was changed.

I agree with the statement made in the article that the tubes run hot. I always used a cooling fan with the unit to keep things cooler. That may be one reason why I never had trouble with the cheap ceramic trimmer capacitor in the front end.

This website is a goldmine of information on modifications to improve various home electonic entertainment equipment.

I grew up with Heathkits, Eico kits, Knight kits and even a few Lafayette, Olson Radio and Burstine-Applebee items over the years. I even did some modifications to surplus military radios for SW listening.

It all brings back pleasant memories.

Joe

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Follow Ups Full Thread

Topic - Ceramic IF Filters and Tube Type Tuners - strijw426 14:20:59 05/12/11 (15)

RE: Ceramic IF Filters and Tube Type Tuners - Neff 08:47:33 05/14/11 (0)

RE: Ceramic IF Filters and Tube Type Tuners - Eli Duttman 17:12:01 05/12/11 (13)

RE: Ceramic IF Filters and Tube Type Tuners - strijw426 17:52:42 05/12/11 (12)

RE: Ceramic IF Filters and Tube Type Tuners - Steve O 18:43:23 05/12/11 (11)

RE: Ceramic IF Filters and Tube Type Tuners - strijw426 19:31:50 05/12/11 (7)

RE: Ceramic IF Filters and Tube Type Tuners - Eli Duttman 18:43:08 05/13/11 (4)

RE: "Buddhafying" the FM-3 - strijw426 05/16/1119:28:47 05/16/11 (2)

RE: "Buddhafying" the FM-3 - Eli Duttman 21:29:12 05/16/11 (1)

RE: "Buddhafying" the FM-3 - strijw426 04:41:27 05/17/11 (0)

RE: Ceramic IF Filters and Tube Type Tuners - strijw426 18:51:51 05/13/11 (0)

I probably don't need to mention it but... - Steve O 19:59:00 05/12/11 (1)

Directional Antennas & Rotators - strijw426 12:03:04 05/13/11 (0)

RE: Ceramic IF Filters and Tube Type Tuners - BFitz 19:12:23 05/12/11 (2)

RE: Ceramic IF Filters and Tube Type Tuners - strijw426 17:29:06 05/13/11 (1)

RE: Ceramic IF Filters and Tube Type Tuners - BFitz 08:11:57 05/14/11 (0)

Follow Ups

RE: "Buddhafying" the FM-3 - strijw426 05/16/1119:28:47 05/16/11 (2)

RE: "Buddhafying" the FM-3 - Eli Duttman 21:29:12 05/16/11 (1)

RE: "Buddhafying" the FM-3 - strijw426 04:41:27 05/17/11 (0)

RE: "Buddhafying" the FM-3

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