If there is no transmit delay, perhaps during the amplifier receive to transmit switch over, the transceiver is seeing an instant of high vswr that activates the rf back off protection. If so, it tak
A couple of comments from a user: The solid state relays do not completely shut off in the off condition; you will have some residual voltage on the output terminal when you might expect zero volts.
50 Ohm, 50W wirewound $3.38 at Mouser Electronics. Vishay stock# 71-HL50-06Z-value. 73, Gerald K5GW In a message dated 2/2/2009 10:05:00 A.M. Central Standard Time, bmaser@tampabay.rr.com writes: I'm
The larger Zeners are available through NTE. Mouser carries them but you may have to find the NTE part# to find them in the Mouser listing. NTE has an excellent lookup system at their website, if I r
Scott, that symbol is for a high voltage feed through assembly. The capacitor is formed by metal plates on each side of the rf enclosure with thin dielectric insulating them from ground. 73, Gerald K
If there is a plate voltage metering circuit, there could be a sneak path for this current to flow through the grid meter. If it does, it would be in the reverse direction compared to normal grid cur
Also, there is a series of Dayton timer modules in the W.W. Grainger catalog. Most are adjustable over a 10 to 1 time range. 120vac on the input terminal delivers about 119 vac to the output terminal
Just curious: is the lowered efficiency because power output is reduced or because the plate input power has increased, or a combination of both? 73, Gerald K5GW In a message dated 3/11/2009 3:35:38
Paul, if you don't get the scale exactly right, you basically change the full scale deflection current by the percentage of the error. ie; a 200 uA movement may end up being maybe 195 uA or 205 uA if
Contact W7QX directly if you need one of his 4CX1600B tubes. 73, Gerald K5GW ____________________________________ From: w7qx@msn.com To: moon-net@list-serv.davidv.net, moon@moonbounce.info Sent: 4/22
Sounds like you might need more drive power. That would increase the plate current swing which will lower the plate load resistance. This would require less plate loading C for maximum power output.
Or, relays in series with a resistor to use up the rest of the 85v. Since the relays are pretty much a constant resistance, a regulator is not needed anyway. As Marv said, this is assuming the 85v ha
Didn't Heath use the ungrounded grids as a way to apply cutoff bias during standby? Seems the internal antenna relays were connected between a -130vdc supply and the grids. The connection to the grid
You are right Joe. It was the SB200 that used the cutoff bias through the antenna relay scheme. 73, Gerald K5GW In a message dated 7/29/2009 8:46:28 P.M. Central Daylight Time, lists@subich.com write
Hi all,in addition to the examples Larry offered, the scheme will also match impedances less than 50 ohms, down to 22.2 ohms if I remember correctly. A two way power divider where two 50 ohm loads ar
Steve, the 260 is a fine VOM but, it is old and the calibration can't be trusted until it is checked with proper equipment. The resistors change value with age and who knows what damage could have oc
OK, I give up; what is a BA rig? 73, K5GW In a message dated 8/10/2009 2:00:34 P.M. Central Daylight Time, km1h@jeremy.mv.com writes: 10X the RL was the way it was done and all the old BA rigs had 1
The 4CX1600U is a coaxial base tube. You build the socket from finger stock and the various cavity parts required for proper operation. I have run one on 432MHz moon bounce for several years and can
Bill, you mean for this to apply to grid driven operation, don't you? In cathode driven service it is more like peak cathode voltage divided by peak cathode current. Note peak cathode current in line
Another way to look at feed through power is the drive power causes an rf voltage to appear between the cathode and ground. This voltage is in series with the plate voltage and the plate power input