[Hallicrafters] Then and Now

[Roger (K8RI)]

The talk about restoration, faithfully maintaining the original, and adding 
solid state rectifiers has caused me to do a bit of reflecting on days past.

Back in the days of those warm glowing tubes when those tubes were a 
freaction of their present cost, we used to do every thing possible to boost 
voltages for just a few more watts, even though those watts would never show 
on some ones S-meter. When solid state rectifiers came along we used them to 
get a bit more plate voltage and few worried much about inrush current. When 
you threw the power switch on you would be rewarded with a resounding, 
"Thump" from within the rig, but I never had the power transformer fail in 
one of those rigs. Besides the whole rig did run noticably cooler without 
the heat from the rectifiers and their filaments which also reduced the load 
on the transformer.  BTW I lived near the beginning of a very long medium 
voltage power line so the AC mains were very close to what we see now and 
the upper limit of the tolerance back then.

Today it comes down to why do I run a boat anchor, or a complete HT32, 33 
and SX 101 station. If it were purely a restoration for display I'd stick to 
being faithful to the original design, but if I'm going to *use* that 
station, I certainly want to prolong its life. I spend far too much time 
fixing stuff as it is. Using properly designed solid state rectifiers with 
current limiting can go a long way towards reducing the heat in the 
transmitter and receiver. They also reduce the load on the transformer 
further reducing the heat and increasing the transformer life. However, I do 
not bother in adjusting the line voltage which normally runs between 115 to 
118. Right now it's 118.

Considering the price of tubes and transformers it certainly makes sense to 
replace the rectifiers with "plug in" solid state replacements. The plug-ins 
also allow the original circuit to be maintained so all you have to do for 
complete originality (with the exception of the caps) is plug the old tube 
type rectifiers back in.

Roger (K8RI)