Re: 18MHz drain Voltage supply Bypass problem
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Barry, Its doing a good 1KW on all other bands so the amp cannot be damaged.
R
On Mon, Sep 18, 2023 at 2:16?PM Barry K4OCS < KK4OCS@...> wrote: If you have blown one or both of the LDMOS outputs your VSWR will be off and it will never load up going into bypass ? Thanks for the note.. however. Over power input is not the issue. I'm using 20 to 50 watts in.
The bypass error starts at 17 watts input
I never have put over 50w in on any band.
Raul W4AWI On Mon, Sep 18, 2023, 14:07 Barry K4OCS < KK4OCS@...> wrote: I had the same problem with my ICOM 7300 I sent my LA 1K back to the factory after they replaced ?one of two LDMOS’s I had them install a new protect board that will put the unit in bypass if it sees anything more than 60 watts. I replace the ICOM with a Yaesu FTDX101D no more over shoot. that project board is not free but it’s very inexpensive. On Sep 18, 2023, at 1:11 PM, Joe Loverti WW8X <jloverti@...> wrote:
? If you do a Google search you should see some reports on an overshoot anomaly?with the IC-7300. I didn't cure my intermittent bypass issues until I started using an FTDX-10. I don't know how widespread this issue is, but I know I had it. My IC-7300 played well with my AL80-B (tube amp) but not with the LA-1K (solid-state amp). Joe WW8X On Mon, Sep 18, 2023 at 12:56?PM Raul J Pla < planet95x@...> wrote: 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
Any?help, appreciated!
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.
73 Raul? ?W4AWI
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