The "typical" anode resonance of a 4-1000A is around 80 MHz. However, with my current design that uses NO suppressor resistors in the anode, I cannot find a resonant dip on my GDO in that region or
How long will you hold to the view that the resistors where of proper resistance value before the oscillation took place when you have no proof? You are making an assumption that the resistors were
Hello All, I currently have a home brew amp which I need to finish which I can make oscillate at the drop of a pin. Would it be of interest to anyone for me to put new resistors in the anode suppress
I am not sure if this has ever been posted to the reflector, but I found this interesting Web site that provides a little more information concerning the testing done by N7WS, so I thought I'd pass i
AMEN Peter! I still have a 4-1000A here that will draw 400ma " on demand". Ive used it several times in a show and tell. The glow really gets attention. BTW, the first year of (1954) Ford/Mercury OHV
Author: w4eto@rainbow.rmii.com (Richard W. Ehrhorn)
Date: Fri, 9 Apr 1999 15:51:48 -0600
? Adjusting C-tune makes little difference in the anode resonance since C-tune is effectively in series with C-anode, which is much smaller. [Richard W. Ehrhorn] <<< A sweeping generalization which i
On Fri, 09 Apr 1999 15:42:05 -0400 "Warren J. Walsh" <warrenw@pentek.com> writes: It has Warren but Rich seems to have his own spin to it. 73 Carl KM1H _______________________________________________
Good point Jon but dont expect a straight answer. In the SB-220 case remember when the amp was designed. Long before the 1500W output rule. When run BY THE MANUAL it will not overheat the suppressors
SNIPPED On 10M which comes first, the cart or the horse? It was agreed by most, (sorry if you were not invited,) that many common suppressors do run hot on 10M and extended use will result in an incr
? _______________ Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: am
? excellent ? Does it have a history of damaging suppressor resistors, Steve? Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures -- FAQ on WWW: http://www.contesting.com/ampfaq.html
? Surely. The 8973 has 160pF of C-anode. At 29.5MHz, C-tune would probably be around 100pF. However, in a SB-220 the measured anode resonant freq. changes little between 80m and 10m operation. Rich.
? I bought new +/- 5% resistors at the radio parts emporium. The resistors were within spec. Approx. Ten minutes later they were toasted during operation on 40m despite the fact that each was connec
? I did not state that the arcs occurred during 10m operation. I stated that the arcs occurred at the open 10m contacts. The photo of the toasted bandswitch in the QST article "Parasitics Revisited"
-- I first worked on an SB220 as a Heathkit tech in the mid 70's. Since then I've owned, serviced, modified or for some reason had my hands inside 20 or 30 SB220s (not the 200 Rich has tested). In th
Author: Dick Green" <dick.green@valley.net (Dick Green)
Date: Sat, 10 Apr 1999 09:53:10 -0400
can be directly attributed to the operator rotating the band switch instead of the load control while tuning up. The physical layout of the tune, load and bandswitch controls makes it easy to turn th
? bingo ? I did not state how many I worked on. My guess is fewer than ten. ? When an amplifier's tank is out of resonance are the tank voltages maximal or minimal? Does it make sense that rotating
On Sat, 10 Apr 1999 19:15:39 -0500 bob alexander <realex@flash.net> writes: (not the 200 Rich has tested). I believe I mentioned that, not Rich. Most of the 220's that I convert to 6M arrive in somew
On Sat, 10 Apr 1999 02:37:57 -0700 Rich Measures <measures@vc.net> writes: Was this one of the mailed in switches? How can you assume the prior condx of any contact before the final failure? There ar