Palstar LA-1K RFI

[N3CAL]

I just picked up a Palstar LA-1K Amp and noticed on the waterfall all the noise it generates when powered on. pics are with amp on in standby attached to a dummy load. Anyone else running a LA-1K see this?

LA-1K ON
https://apache-labs.com/community/downl ... ew&id=2905

LA-1K OFF
https://apache-labs.com/community/downl ... ew&id=2904

Cal / N3CAL

[w-u-2-o]

Wow! That looks so bad it the amp must be broken somehow

[alemrush]

My opinion. Looks like a filtration problem from your dc supply ( 50VDC @42A , switching power supply) .



André

VA2WR

[N3CAL]

I contacted Palstar and they refuse to do anything! They claim those signals are down more than -150db and would be a S1 signal which is no problem! With antenna attached I can hear those peak birdies and it's annoying!

Cal/N3CAL

[w-u-2-o]

Palstar needs to check it's math. The peaks are at -105, which is approx. S4. Those are big signals!

[kc2rgw]

That is in NO way normal. I own an LA-1k and it's not even something I've ever noticed. Your amp likely has a broken power supply filter in it.

[K9RX]

Wow indeed. That is horrendous and (the peaks) would be noticeable on any band except possibly 160M. Totally unacceptable - something wrong with the amp. Palstar needs to step-up and fix it.

Gary
K9RX

[WR4N]

I just picked up a Palstar LA-1K Amp and noticed on the waterfall all the noise it generates when powered on. pics are with amp on in standby attached to a dummy load. Anyone else running a LA-1K see this?

LA-1K ON
https://apache-labs.com/community/downl ... ew&id=2905

LA-1K OFF
https://apache-labs.com/community/downl ... ew&id=2904

Cal / N3CAL

I’m going out on a limb here ... but I’m guessing you bought that used. Correct?

[N3CAL]

Hi David, the amp is brand new. I ordered direct from PALSTAR in January and received in late April 2022.

Cal / N3CAL

[N3CAL]

6/24/22 UPDATE: I shipped amp back to PALSTAR for warranty repair. They confirmed the RFI issue when using the amp on 120 V. (I currently don't have a 240V drop here in the shack so it's 120v only for now). Their fix was adding a ferrite core inside the internal 50V power supply. The internal ferrite fixed the problem! No more RFI! Turnaround was just under 3 weeks. They mentioned they were going to add the ferrite FB77-5621 core to all their production units now. Most of their testing is done on 240v so it wasn't noticed during production. The amp is back in the shack and running great!

Cal/N3CAL

[w-u-2-o]

Good news!