On Oct 13, 2004, at 10:29 AM, craxd wrote: 
 
Manuel, 
 
I seen some on Ebay for sale the other day. They had several different 
band switches and also several roller inductors. To by a new roller 
inductor, you might want to try Oren Elliott as I'd say their pricing 
would be much less than anything from Henry. The only frequencies you 
might run into problems with a roller inductors would be 50 MHz (6 
meters). Roller Inductors have been used in homebrew and a few factory 
amps for years. The main thing, say for 15-10 meters, you need to make 
sure the coil will carry the current. If it's not large enough, the Q 
will be affected greatly. Here though, you could have a large DPDT 
relay to throw in a 10 meter coil, and use the roller inductor for 
lower frequencies.
  No relay or switch is needed for the added 10m section since, for 10m 
operation, the roller L is set to zero so the only inductance in the 
tank is the stray L in the roller L and the 600 or so nH in the 10m 
section.
 Oren Elliott:  http://www.orenelliottproducts.com/index.html 
 
Will Matney 
 
 Manuel R. Alonso wrote: 
 
Hello, 
 
 Does anybody know of a good source for reasonably priced 
bandswitches? I called Multi-Tech industries and a decent switch 
costs $250.00. The nice one's at surplus sales of nebraska are also 
up there in price. 
How about uning the Henry Roller inductors in lieu of bandswitch / 
tapped coil. The Henry rollers are less than $200.00 ea and that is a 
complete assembly. 
Does the roller present a problem at the lhigher bands were very low  
inductance is needed in the Pi circuit? 
The amp will have two 4CX800 russian tubes. tube RL = 975. 
 
Thanks 
 
Manuel R. Alonso 
 
KC4MNE
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  Richard L. Measures, AG6K, 805.386.3734.  www.somis.org 
 
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