On Nov 11, 8:57*am, "D. Peter Maus" wrote:
On 11/11/11 24:15 , wrote:

On Nov 11, 12:04 am, David
wrote:
My guess is that the cost you would have to charge to recoup the time
and effort you put together in coming up with such a design would end
up making such a set *much* more expensive than just going to a ham
fest, buying a Hammarlund in good shape, and fixing it up. Or even
paying someone else to fix it up.

* I already have a R-390, two Hammarlunds and a Racal....I wanted to
manufacture something. Or at least think about it.

* *Certainly worth thinking about.

* *Maybe worth doing. But consider:

* *Tubes are getting harder to come buy. Not that they can't be had.
And after an EMP, they're likely to be as available as working SS
devices. But there are inherent issues with Tubes. One is that they
use a LOT of precious energy, that in a survival mode situation is
best conserved for other applications, or longer listening. Another
is that voltages are much higher than those that can be recovered
after or during a crisis with ease. Low voltage, low current devices
are going to be more desirable when energy is in short supply.

* *But, more importantly, tube receivers aren't necessarily less
prone to damage by EMP than SS receivers. In fact, there is
empirical evidence to suggest that SS receivers can be made to
survive an EMP where a tube receiver will not.

* *Your best options, then, would include building a reasonably high
performance receiver with readily available common parts, and take
measures, such as a Faraday cage, and effective grounding/input
protection measures, to render your station if not immune, then more
resistant to stray or induced hostile voltages.

* *Now, you have a practical, and manufacturable, product.

-wrt- Faraday Cage :
Old Metal {Steel} Garbage Can with a
tight fitting Lid. -store-holding-
+ The Solid State AM/FM/SW Radio
+ Plenty of Batteries
-or- Re-Chargeable Batteries and a
Solar Charger

-no-tubes-required- ~ RHF