[Elecraft] KPA500 receive loss

Just noticed this evening that on 160 I lose about 6 dB of rx level (noise and signal ) when I go from STDBY to OPER. On 40 maybe a dB or so , on 20 no change -- On160 almost always am using RX antenna so am not going thru the KPA but this evening had Tx ant on RX . Maybe has always been that

[Elecraft] KPA500 receive loss

There was a similar report fairly recently. I copied this to my KPA500 notes: "Reported problem(s): Receive signal is attenuated when in operate. Receive signal is normal when in standby. Problem(s) found: Confirmed problem. Found that D8, D9 and R7 in the T/R circuit had failed. Repair(s) perf

[Elecraft] K-3 does not turn on.

Greetings, this is my first approach to the qth.net. My K-3, assembled from the factory, quite a few years ago, shows the very first failure, it does not turn on. Voltage at the power socket is 13.5VDC. Where shall I look? Vy 73 Antonio - CU8AS _

Re: [Elecraft] KPA500 receive loss

This happened with my backup amp at the contest station on J6. I left it connected by accident overnight (too much rum) and we had some static storms. Took out the pin diodes (well, more accurately the diodes that act like PIN diodes). When put in operate, the receive drops by 30+ dB but still t

Re: [Elecraft] KPA500 receive loss

Would a gas discharge tube save the sensitive parts? David G3UNA > On 05 June 2021 at 16:20 "Dr. William J. Schmidt" wrote: > > > This happened with my backup amp at the contest station on J6. I left it > connected by accident overnight (too much rum) and we had some static > storms. Took o

Re: [Elecraft] KPA500 receive loss

I'm sure you could invent many ways to protect these parts (gas tubes, sacrificial TVS diodes, fusing, etc.). The best way, of course, is to disconnect it (which of course I did not do). These are low voltage parts on the receive side path so I don't know if a gas tube would be appropriate he

Re: [Elecraft] KPA500 receive loss

Does that confirm correctness, or brokenness? 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources On 6/5/21 8:20 AM, Dr. William J. Schmidt wrote: This happened with my backup amp at the co

Re: [Elecraft] KPA500 receive loss

This doesn’t really have the signature of pin-diode failure. When the pin diodes fail you generally get major signal loss across all bands. The description simply does not match that diagnosis. I would ask for further information: * Is there any change in 160m transmit operation (change in drive

Re: [Elecraft] KPA500 receive loss

Even (sub) nano second (ns) fast acting gas tubes are primarily not a safe solution to RX front end burnout protection. Semiconductors: Issues: Energy Protection level, RX Intermodulation prevention. There are however some fast semiconductor diodes (ESD protection) available with low capacitance

Re: [Elecraft] K-3 does not turn on.

Hi Antonio, Am 05.06.21 um 16:23 schrieb Antonio Madeira: > Greetings, this is my first approach to the qth.net. > > My K-3, assembled from the factory, quite a few years ago, shows the very > first failure, > it does not turn on. Voltage at the power socket is 13.5VDC. > > Where shall I look? C

[Elecraft] Elecraft CW Net 19th Anniversary Announcement

Good Evening,    This week was sunny and hot.  Plants and insects grew very well.  I was able to build three antennas but only raised one of them.  I am coax challenged.  A few more runs plus an antenna switch will be on order soon.  Four antennas should give me paths into much of North Americ