Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Rick NK7I
I'm glad you found the cause and a fix. I'll add that, in my experience, 40M is always the most problematic band for causing RFI problems.  In a vehicle or home, it seems that a LOT of 'stuff' is sensitive to 40M.  160M comes in second for that status. 73, Rick nk7i On 11/21/2023 2:55 PM, A

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Andy Durbin
"I should be able to fix the problem with better decoupling and/or choking of the breakout box connections." Problem fixed by adding a 0.01 disc ceramic caps on each of the 4 RCA keyline jacks on the breakout box. I should have included them when I built it. Interesting problem though and all

[Elecraft] OT: Wiring A Continent : The U.S. Transcontinental Telegraph Line

2023-11-21 Thread Wayne Burdick
I highly recommend this fascinating first-person account. You might want to skim over the parts about political infighting to get to descriptions of the route, procurement of poles, Indian encounters, and inclement weather. (And we thought Field Day setup was challenging.) http://www.telegraph

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Jim Brown
On 11/21/2023 9:03 AM, Andy Durbin wrote: I should be able to fix the problem with better decoupling and/or choking of the breakout box connections. That suggests bonding and grounding may not be sufficient. Every chassis that is part of the station must be bonded together, and that bonded to

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Kevin McQuiggin (SFU)
Hi Clay: I concur with your comments re cheap connectors. I have had cheap connectors melt, short, go open and mechanically come apart. Fortunately these were in the days of big old tube-based robust rigs. I gave up on bargain connectors about 35 years ago. I’m happy to pay substantially

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Andy Durbin
I followed up on the RFI theory and quickly found a solution to the problem. My TS-590S has a homebrew breakout box on the REMOTE connector. This breakout box provides key line level shift and key line interrupt for my SteppIR. The TS-590S ALC control line is on this cable but is not terminate

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Clay Autery
NOT directly related, and MAY not be related AT ALL but consider clearing the tuning solutions stored on a section of the band where it oscillates and let it RE-tune at a power level JUST below what it was oscillating at Then turn her up and see if it still does it.  Likely will, but j

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Clay Autery
Listen to Jim, guys.  THE most frustrating thing in troubleshooting is when the "trouble" is in the cheap/low quality parts used in an assembly.| ALWAYS buy the best you can find/afford.  Buy the best; buy once. I have a FEW more vendors than Jim, but his point is nonetheless valid and should be

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread jerry
Is the internal autotuner of the TS590S on? - Jerry On 2023-11-21 04:50, Andy Durbin wrote: Thanks to those that replied with suggestions. This morning I ran some additional testing. I found I could induce the oscillation at 70 W KPA500 output power. With KPA500 switched to STBY I

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Andy Durbin
I found that the power for onset of oscillation is strongly dependent on frequency: 7.01 C0,L0, SIDE T - max no osc 108 W 7.02 C0, L710, SIDE T - max no osc 118 W 7.03 C0, L710, SIDE T - max no osc 129 W 7.10 C0, L710, SIDE T - max no osc 222 W 7.20 C47, L820, SIDE T - max no osc unknown no

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Andy Durbin
"Perhaps check and see if the drive from the TS-590s is varying, or if the gain of the KPA500 is changing. What does the output meter on the 590 say when this happens?" TS-590S power meter does not change nor does TS-590S indicated SWR. However, I did find that TS-590S ALC reading is cycling.

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Victor Rosenthal 4X6GP
Perhaps check and see if the drive from the TS-590s is varying, or if the gain of the KPA500 is changing. What does the output meter on the 590 say when this happens? 73, Victor, 4X6GP Rehovot, Israel Formerly K2VCO CWops no. 5 http://www.qsl.net/k2vco/ On 21/11/2023 14:50, Andy Durbin wrote:

Re: [Elecraft] Power oscillation problem (KPA500+KAT500)

2023-11-21 Thread Andy Durbin
Thanks to those that replied with suggestions. This morning I ran some additional testing. I found I could induce the oscillation at 70 W KPA500 output power. With KPA500 switched to STBY I could run 100 W from my TS-590S with no anomalies. The only change in the antenna system configuration