ORIGINAL MESSAGE: REPLY: I'm wondering if some seals are better than others. Many years ago Tektronix stopped making CRTs out of glass and went to ceramic because the seal was better. I suspect the s
ORIGINAL MESSAGE: REPLY: Ten times the plate load impedance? For the typical 160 meter amp running 3 kV and 800 mA with a plate load impedance of aprox 2200 ohms, that would require a choke with a re
ORIGINAL MESSAGE: REPLY: I keep forgetting about you QRP guys. I was talking REAL amplifiers. :-) 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com
ORIGINAL MESSAGE: REPLY: If you mean the series feed where there is a bypass cap at the junction of the tank circuit and RF choke, there is very little RF there and practically any choke will do. Or
ORIGINAL MESSAGE: REPLY: Some amps do that, but IMO a better approach is to use a choke with no resonances in any ham bands. The one sold by RF Parts meets that requirement. I have used that one in s
ORIGINAL MESSAGE: REPLY: If you don't find a cheaper source, Mouser carries these as part number 534-7677. Go to www.mouser.com and enter the part number in the search box. Good luck on your project.
ORIGINAL MESSAGE: REPLY: Either metal-film or metal-oxide resistors are significantly more stable than carbon comp. Their only possible disadvantage is that some values may exhibit more inductance th
ORIGINAL MESSAGE: REPLY: Before I retired from the avionics biz, I worked at a company that had a $10,000 HP impedance analyzer. The company didn't mind us using it during off hours and I learned a l
ORIGINAL MESSAGE: REPLY: Next time the XYL starts yapping at you, let her see you slowly reach for the switch..... :-) 73, Bill W6WRT _______________________________________________ Amps mailing list
ORIGINAL MESSAGE: REPLY: Plain old rubbing alcohol will do the job and won't harm any plastics. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com ht
ORIGINAL MESSAGE: REPLY: By my calculations, 240 VAC would give you 376 VDC across the caps. You're ok. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contestin
ORIGINAL MESSAGE: REPLY: If your antenna is an open circuit for DC as many are, there would be a HV pulse applied to the coax through the plate blocking cap. If the DC leakage on your coax and antenn
ORIGINAL MESSAGE: REPLY: That's ok until someone down the road changes antennas. You may not be the only owner of the amp. I like to think one of my grandkids might someday use grandpa's old amp. :-)
http://www.edn.com/contents/images/159688.pdf As the author points out "Of the three basic passive components?resistors, capacitors, and inductors?inductors are the least ideal and, therefore, the mo
ORIGINAL MESSAGE: REPLY: A resistor in place of the choke is not a good idea. If the blocking cap shorts, the resistor will almost certainly blow open and you are right where you were if there was no
ORIGINAL MESSAGE: REPLY: A better approach, IMO is to build a circuit that is stable without any parasitic suppressor at all. Tubes that are physically small such as the 8877 lend themselves to this
ORIGINAL MESSAGE: REPLY: Sounds good to me except I would hard wire it inside the amp so that years from now, someone who doesn't know what it's there for might discard it because "it doesn't do anyt
ORIGINAL MESSAGE: REPLY: A great post and an excellent summation. Thanks, John! 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com http://lists.conte
ORIGINAL MESSAGE: REPLY: That is quite a remarkable statement. Before you besmirch Rich's reputation any further, can you back up your statement with names, dates and facts? 73, Bill W6WRT __________
ORIGINAL MESSAGE: REPLY: You are missing the fundamental purpose of a parasitic suppressor. It does not "trap", "load" or "absorb" the parasitic. Instead, its job is to reduce the gain at the parasit