RF2K-S Solid State Amplifier Testing Demonstration

Cory, W3CDG - Production Manager for DX Engineering, talks about assembly and preliminary testing for the new RFK-RF2K Amplifier Kit.
www.dxengineer...

[@JbirdlLester]

How Much does this Amp Run I'm Very Impressed!

[@205a2]

No tune? Or is there an automatic tuner inline? Dunnyload? Little help, I would love to have an autotuner that works that fast.

[@MojaveJazz]

Do you have to pre tune the bands and frequencies and store them or does it tune on the fly?

[@nickp.4915]

The Kit is really not that involved to get up and running. You will need a DVM, a 1KW Dummy load, a radio to use as a test rig with variable power output, a couple of patch cables, a single RCA cable for tx/rx switching to hook the amp up to your radio, a power meter, soldering iron, small qty of solder and a small flat screwdriver\tuning tool. You will also need a computer and an SD card reader\writer to write the software onto SD card to install into the Raspberry Pi. You will also need to hook up various usb and video cables to their appropriate jacks inside the amplifier (all cables included). You can get the amp running and calibrated with the 120VAC cable (included) the 240V cable is only needed for full power running after everything is set up. The basic concept is that you install the Pi and it's cables. Write the software to the SD card and plug it into the Pi then power up and bypass the PA board with an included pigtail cable you solder to the internal coax that feeds the PA Pallet in order to bypass it. you then put various levels of RF on various bands through the amplifier in both the forward and reverse directions to adjust the calibration pots for forward everse power. You will need to make two voltage adjustments at points on a board with other pots, and one variable capacitor adjustment. After all of those adjustments are complete you remove the pigtail and make the only two required solder connections by connecting the internal coax to the RF Pallet board. After that connection is made you change a couple of plastic computer type jumper pins from one position to another and then slowly test into your Dummy load on various bands and power levels while making a few more fine pot adjustments. Walking through the whole process the first time takes a couple hours, but really is not difficult. I could see after aligning a couple of these the average Ham could go through the entire alignment in about 30 minutes. As of right now the software\firmware is very limited, and many of the promised features are not available yet, although the amp works great with just the tx x line and coax hooked up to the transmitter. Band switching is instant. Overdrive protection is instant and reliable so far, as I have accidentally over driven my amp a few times during my initial 10 minutes of using it after finishing the set up. There was no harm no foul... hit the reset on the touch screen reduced my drive and carried on. I have been running mine for the past two weeks at about a kilowatt SSB PEP output since I am still on the 120VAC for now. The amp only requires 19Watts of PEP SSB drive to attain 1KW on 20\40 where I have been using it so far. At 1KW this amp loafs along like a kilowatt is nothing. When the internal fans do kick on I don't even notice them, since quite honestly the amp is quieter than the ambient noise in my shack when the radio is on anyway. I have done a "keydown" test a few times on a few bands but only to a Kilowatt and only for 7 minutes as my Cantenna is only rated 1KW for 10 Minutes. The amp put this energy into my load effortlessly for those 7 minutes. Cooling fans were running and the temps were in the 50C-55C range. I have not had much chance to use the internal tuner unfortunately. It does not quite match the tuning range of my MFJ-998 and my Hex Beam needs some tweaking and has a band or two that are just out of tuning range of the RF2K-S but well within the range to be tuned by my MFJ-998, so I am not thrilled I still am forced to use my external tuner at least until I get a chance to tweak my hex beam. Idea was to eliminate the external tuner. I'm guessing this will be possible, I was just a bit lazy when tuning the hex since it has 8 bands and was impossible to get them all perfect. So far I am enjoying the amp but wish more of it's promised features were currently available. Would also love it if it was possible to eliminate the RCA TX\RX cable and still maintain the speedy switching. Dont know if that will happen but it would be great to get the UDP or even if the amp just detected drive on the input coax and went to action without requiring the radio to tell the amp to transmit.

[@dl4qb-andre938]

How long can you do key down without overheating or annoying fans?

[@JCB12345]

Can RF2K-S be used for VHF 136-144 ?

[@markharris2539]

When the ATU is not bypassed, what range of SWR will the amp tune?

[@jimriffett6704]

What's the price of the 2K solid

[@andrewhamop6665]

Damn, that's one impressive amp. If I had the spare cash I'd love to buy one. 73 de W8IJC

[@johnm.karian5295]

Heard Tim, K3LR, say this is available as a kit. Are the technical writers US-based or European? - Would be a fun project - KB3H

[@nickp.4915]

Speaking of the KIT... Any details on what will be required of those of us whom have ordered this in kit form. It sure would be nice to know what will need to be done before the amplifier arrives so we can prepare...

[@corygibson5770]

The build manual is written in German and has been translated to English. However we have been working with them on getting the translation cleaned up. Reinhard has been great to work with and very helpful in teaching us everything there is to know about this amplifier!

[@corygibson5770]

@@nickp.4915 - We have a beta build manual, and will try to get it posted on the website early next week. It is a pretty easy build. You need a good dummy load, soldering iron, accurate watt meter, volt meter, and some screwdrivers. Actual build takes almost no time, calibration takes a bit longer, but at this point I can run the entire calibration in about 15 min.

[@johnm.karian5295]

Cory Many TNX. Did a ton of Knight and Heathkit projects. Amazing how, pre-CAD, they were able to do ‘exploded’ views of chassis alignments - truly an art. Looking forward to you bringing this to market soon - KB3H

[@edwardsavela]

First, when will the assembled version be available? Is there a waiting list for the assembled version? I used to build but today it's plug and play only. Hi hi... Is it user selectable for F or C temperatures? Nice looking amp. I was going to buy the Expert 2K with ATU but decided to wait and see what this one does. One of them will be a belated Father's Day gift to ME! And today is Father's Day! Ed/K8EA

[@corygibson5770]

Ed, There is no waiting list for the assembled version yet. It cannot be offered for sale until the FCC Certification is complete.

[@user-ew2xb1tj6y]

What's the price on the amp kit?

[@825saturn]

$5000.00

[@dl4qb-andre938]

@@825saturn LOL...That´s "cheap"

[@mikegianfrancesco9431]

1800 cant use that on air

[@markgriffin2285]

I'm sure you have to connect the radio somehow to the amplifier. If you are not using a CAT control, than how does this process work? I currently have an Expert MB1 SDR as my rig. KB3Z

[@RadioWhisperer]

I don't know for sure, but based on his comment about RF sensing I would bet that the amp includes a very fast freq counter and it doesn't key until it's set the right band. But, this is just supposition based on the video. It makes sense, they're not reading the freq to tens of Hz, just what band it's on. That you can do fast..

[@nickp.4915]

Yes it sure does look as if there will be no CAT connection or any other connection required other than the power and the coax, and of course the optional LAN and PureSignal for those radios equipped as such.

[@corygibson5770]

It does frequency sensing down to about 1 kHz. (you can see the frequency switch to almost the exact radio frequency) Honestly, I was doing things I would never do with my current amplifier just to try to break it. Between the fast controller frequency sensing, and the pin diode tx/rx switch, band to band switching, including tuner is around 15 ms. TX/RX only is measured in microseconds.

[@RadioWhisperer]

@@corygibson5770 considering the incredible ease of use and how much consistent power this puts out on very little drive, this is an impressive piece of gear.

[@markgriffin2285]

I was looking at the Specs and it has an ATU. How much of a mismatch can the tuner adjust for? I am using my SPE 1.3K with a Palstar HF-Auto. The only bands where SWR may need to be adjusted would be 80 and 160M. Any thoughts on this? Mark KB3Z

[@W8ASA]

You ran it for six hours on FT-8, but at what power output? Ken W8ASA

[@bryanwollenberg1113]

1.5k presumably. Mine will do that all day long.

[@dl4qb-andre938]

@@bryanwollenberg1113 and what about the fans after that time?

[@bryanwollenberg1113]

@@dl4qb-andre938 Unless it's the summertime and the shack is a little warmer, I don't really get fan noise at all from the amp. I get way more fan noise from my radio running FT-8.

[@dl4qb-andre938]

@@bryanwollenberg1113 Sounds too good to be true :-) Just some more years to save the money,hi!

[@nickp.4915]

I'll be damned! kzbin.info/www/bejne/b5mwcnunpZ55hNk looks amazing! Nice to actually finally see a working video after thirteen months of being strung along waiting with just about the worst transparency to your customers that I, for one, at least have ever experienced with ANY company. The near silence by DXE over the past thirteen months has been deafening... Cant wait to finally receive my order, hopefully we will finally be QRO by July 4th weekend!

[@thebrain4239]

The RF2K is a Splattering POS proudly why DX Engineering dos does not sell them any more? Nice Kit for HF amp but sorry not clean at all.

[@steveparker7763]

I get it, why...... but the vents on the front are ugly