** As seen on an oscilloscope, with 1500W-pep into 50-ohms, the peak to peak V measures a bit over 750v. - There is more than one PIN diode in a T/R switch. During receive, one of the PIN diodes con
** As seen on an oscilloscope, with 1500W-pep into 50-ohms, the peak to peak V measures a bit over 750v. - There is more than one PIN diode in a T/R switch. During receive, one of the PIN diodes con
** 1500W into 50-ohms =s c. 775v p-p. To prevent a PIN diode from conducting at any point during the cycle, at least 800v of reverse bias is needed, provided the SWR was 1 to 1, otherwise the PIN di
? The max-signal peak-V on the anode is a bit less than double the anode supply V, or, in this case, a tad under 8kV. In dry air, 8kV can jump about 0.31" or 7.8mm. Rich, AG6K, 805-386-3734, www.vcn
** With people making the rules who do not understand SSB and dipole antennas, virtually anything is possible. cheers, Colin Rich, AG6K, 805-386-3734, www.vcnet.com/measures
Does anyone know why there is an amplifier ban on the new 60m band? I have listened there and it appears to be a vast wasteland, totally uninhabited by humans. Rich, AG6K, 805-386-3734, www.vcnet.com
** -- Brad Thomas' design was basically ok for its day. However, a few circuit improvements are in order. One problem with the LK-2000 is that the HV electrolytic filter caps run on the ragged edge
** good point. In a TL-922 it looks like there is room, the filter C is good for 4kV, and the bandswitch has a breakdown potential of 5kV, so it should be possible. ** my guess is 10 - 20 volts posi
** The problem is that 3-500Zs don't idle the same as 4-400As, so a few manoeuvres are in order. The battle plan: 1. Short the bias zener. 2. Increase the anode PS potential by c. 500v in order rais
** Using 120VDC, and a series-R to limit I to 80mA, a 26v HC-1 or RJ1A will make and stop bouncing its NO contacts in 1.8mS. Using a 26v PS, the measured speeds were 6 - 7 mS. Rich, AG6K, 805-386-37
** The rub is that power supply components don't do well with RF. The antenna is probably a better place to put RF. ** Current is not lost in a C or an L because only the voltage/current phase relat
... ... ** Yea, verily. A simpler solution is to replace the lethargic relay-option with a 300v/0.5a NPN switch. ** amen Rich, AG6K, 805-386-3734, www.vcnet.com/measures
** Good point, Peter. If L-networks were resonant at the working freq., they would be a virtual short-circuit. To do their job, XC must not = XL. A Pi-network is two L-networks in series. The apples
** What is the price for (100) GH1 Gigavac? relays? Where does one find the price list on their Web site? ** In order to speed up a GH1-12vdc sufficiently to use with a modern transceiver, one would
? The toasted BS contacts can be removed by drilling out the rivets. New contacts can be fastened in with #0-80 screws. If the 10m and/or 15m contacts are burned, the most likely cause was an interm