Re: 18MHz drain Voltage supply Bypass problem
|
Barry I will try all this. Good idea to weed out stray RF issues and other things. I have a dummy load to try as well. I hope I find a fix before spending $$ on UPS trips and hoping I dont get hit with a repair bill too.
Raul W4AWI
On Mon, Sep 18, 2023 at 2:30?PM Barry < barplo@...> wrote: Raul, ? Here is what I would do. 1.8:1 will not put the la1k into bypass, so I would take the tuner out for 17m testing. See if it still goes into bypass. ? The La1k goes into bypass for 2 reasons. SWR or BYPASS (SWR means you have other issues such as coax or ant) Bypass means it’s a power thing. ? If the LA1K sees any drive over 50w it goes into BYPASS. It also will go into BYPASS if iD=42.5 or more. ? Take everything out of line. Swap out even the patch cord from radio to Amp. (if no swap check or redo the patch cord). Also Take out anything in between radio and amp such as a QRM eliminator. ? If it does it even with a dummy load you have issues which really, from my experience from friends in local community who had a scope (RIGOL) to see exactly what is going on, it could be a cheap solution to Your problem without sending in radio or amp such as using ALC cord to the amp and using the built in ALC in the LA1K. ? Also, not sure if your using RF sensing or Direct cable. If RF sensing, you could try Direct cable. ? I have been down this road with my FTDX5000. I know its not the same radio, but I believe the problem solving techniques are similar if not the same. ? Hope this helps. ? Barry VE6UM ? ? ? I started using my 2022 LA-1K this week in earnest. I was checking the power on each band as well as some CQs on CW or answering?some SSB CQs. Testing bands 40m to 10m I found a problem on 17m (18MHz) Running the IC-7300 with just 30-50W into the amp, I saw 900 to 1050W on all bands except 17m. There it goes into bypass, even dropping power to 15W in 300W out I get the?+Vd bypass.? Going down to 10W in 200W lets it keep working.. I made a 4 min video and a couple of pictures in case Palstar needs to see this. Is there an internal adjustment I can do or some testing I can do inside to avoid the shipping to and from Palstar? The book only has this text below Bypass+VD: [as seen on display] Amp is in BYPASS to protect from loss of +50V, drain voltage supply. The indication should clear in a few seconds. This occurs when operating on 120V, if Drain Current (Id) exceeds 32 Amps . Solution: Switch supply voltage to 240V, or If operating on 120V, Reduce Drive Power BTW I'm using the HF-Auto tuner as well. The antenna is at 1.8:1 and the tuner gets to 1.05:1 easy.
|
