[Milsurplus] Saddle on a cow

[hwhall@aol.com]

THIS. Yes. :-)

We can build much better from scratch. Like, if we need battery power for something like Field Day or POTA events, & maybe using some of the parts from the old chassis (e.g., neat-o tuning drives).

I think one of the reasons for owning the old radios is to experience them AS old radios. No one really needs to hack them as Novice ham station gear anymore. Unless, of course, we're recreating our old Novice days, in which case there are plenty of already hacked units to play with.

Wayne
WB4OGM

On Sunday, August 31, 2025 at 12:16:19 PM MDT, Ray Fantini via Milsurplus <milsurplus at mailman.qth.net> wrote:

Years ago, I wasted a lot of time trying to solid state some vacuum tube devices. One of the subjects was a BC-348 but at the end of the day concluded that because vacuum tubes are high impedance low current devices and most solid-state devices are high current low voltage it’s a fool’s errand. Inter stage coupling in tube circuits are most often transformer base, a voltage device that by its very nature opposes current changes and solid-state devices are capacitor coupled that are all about current changes. Yes, many old solid-state receivers use coils in the RF stages, but they are designed to take advantage of the low impedances. Later in life I learned to accept that things are what they are and often that’s enough. There are more tubes in the world then devices that use them, just look on eBay, beyond being able to say you did it what’s the point?

Just spent a lot of time removing a 6AK5 front end someone built into a BC-348 and don’t think it had that much of an improvement for the amount of work they did. Changed it back to original layout with a 6SK7 and just for fun tried a 6AC7 and did see a small improvement with that and its easily reversible if you don’t care about twenty meters, but no longer have any desire to try to gain improvement by solid stating something like that.

But that’s me, your results may vary. After all we are all free to do what ever we want with this stuff and I am certain someone with more knowledge or experience can prove me wrong.




Addendum - Jfts / FET technology are voltage-controlled devices and I know someone is going to point that out but the smaller voltages that they operate at will produce smaller fields.  Just wanted to squeeze that in before someone points that out! 

 

Ray F/KA3EKH


______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html