[AMRadio] Another question to ponder

[CL in NC]

Has anyone ever researched the need for tube shields on all tubes, versus just some tubes?  Talking about the standard shiny metal ones, not the heat dissipating ones.  On this SP600, there is a tube shield over the 6AL5 bias rectifier.  Why?  Did Hammarlund get a deal on 7 and 9 pin sockets with integral shield bases?  If you have a string of IF tubes, what is to be gained by shielding every one of them, maybe just every other one if they are in a line.  Even the HFO, unless you are running multiple receivers side by side at the same time, what issue from the HFO radiating a signal is there?  If you remove shields and re-peak circuits, would things drift around?  Does the shield keep the tube at a constant scorching hot temp and that keeps things stable?  You can find shielded 6AQ5's, the hottest, leave your finger prints on the envelope tube ever, some are shielded, and some have a cutout shield and many are open to the air.  Is there a real use for a shield in a  vintage receiver in a heavy metal cabinet, other than to protect the tube if you drop something in there?  Other than a heat reducing shield, is there any benefit for the shiny shields that reflect heat back into the envelope on every tube in a radio?

Just wondering.

Charlie, W4MEC in NC