HF Amplifiers Explained! - Ham Radio Outlet
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- เผยแพร่เมื่อ 2 ส.ค. 2024
- HF Amplifiers Explained! - Ham Radio Outlet
HRO Anaheim Technician Bill Scholz (W1HIJ) meets with Julian Frost (N3JF) to tell us how to safely and correctly tune an HF tube amplifier.
Products shown in this video:
MFJ-250: hro.net/aDBvb0d6N2Y
CN-501H: hro.net/ZGUrVVNmZnY
TS-590SG: hro.net/cHozTHRjMkY
AL-811: hro.net/b0RCU2VwQ0Y
Ham Radio Outlet: www.hamradio.com - วิทยาศาสตร์และเทคโนโลยี
Wow this guy has a fantastic broadcast voice 😊
He really does!
He’s got a great FM radio voice 😊
Great video, thank you for putting this info together, great help!!! I especially liked the "dipping" of the Plate, never quite understood this concept and Bill's explanation went a long way in understanding this concept. Thanks again, will put this video to good use!
Glad it was helpful!
Best all time HRO video ever Done
This was great. I've had an AL-811H for almost 20 years but still managed to learn some good tips from this!
this was the best video on the 811h amplifier yet thank you
Thank you!
One of the best video's I've seen on this. Thanks Bill. You are a Gr8 Elmer. 73's, K8JAZ 😎
Hard to believe I ran a homebrew 811a x4 50+ yrs ago and they're still around. I ran them cool for 800w on CW and worked the world like crazy.
Nice job by a very fine gentleman.
Thank you sir!
Well done Bill.
I have searched all over the net for a video to help me better understand setting up and tuning the AL-811.
This video has been THE BEST video I have found. Bill took his time, explained what everything was, walked his audience through how to successfully get the AL-811 working..
Thank you Bill and thank you HRO for producing this video. 73s de KD8VSP
Check W8JI’s tutorial. Lasts about 40 seconds.
So I do have one followup question.
I have the FT991A. You talked about increasing the wattage on the radio to increase the wattage on the AL-811. Does that same theory apply to using the FT991A. 60 watts on the radio to increase the power on the amp?
Hope this makes sense, I am still a newbie with this. 73s de KD8VSP
@@stevenbata2336 yes
@@stevenbata2336 The steps are the same regardless of the radio. That's why Bill didn't talk about how to adjust the radio, as each radio is different.
Makes me appreciate my LDMOS Amplifier that much more.
Yes, at nearly twice the price per watt, they are certainly good to have!
@@HamRadioOutlet Absolutely plusses and minuses. At nearly twice the price, but with a band control cable.. All I have to do is push 1 button and feel it heat up :)
Bill you did a great job with the video. You answered all of my questions about the Ameritron al811 amplifier. Thank you very much .😂 73 AE4OY WILLIAM A. PEACOCK, Sr.EM-81UF Blackshear, Ga
Glad we could help!
Very good presentation! Thanks!
Thanks for watching!
Thank you. Great demo
Outstanding presentation. Clear and concise. Thank you for sharing your knowledge and pass it on to the next generations.
Thanks Daniel.
What a good explanation you give! Thank You for your time.
Glad it was helpful!
Excellent thank you!
I bought my PW1 from HRO Anaheim! :)
Great video
Thank you.
You almost need to take out a mortgage to buy an amp these days. Tube amps run about $2-$3/watt, solid state $5+/watt.
KC5RJL
Houston, TX
Agreed, they certainly are expensive! I wonder if having an amp makes ham radio too easy? I know that when I break through a pile-up using only 5 or 10 watts, or complete a QSO where our mutual signal reports are 5-7 and the remote station is using a 5 element beam and 1,000 watts and I'm using an EFHW thrown into a tree and 10 watts, I'm pretty happy!
I got the same setup
Interesting video thank you, I recently bought an old Yaesu 2100B. It seems to work fine, 50 watts in 400 watts out. I’ve been tuning as you describe but notice that more often than not to achieve maximum power the load control is almost fully counter clockwise. Regardless of antenna. I wondered if you had an idea why this might be. Thanks again.
What are the correct connection cables I need to hook my Yaesu FT-710 to a Ameritron 811-H...IE: Linear 8 pin out of the transceiver, and the ALC cord and the keying cord ?
Bil is A GREAT Teacher. Thankyou Sir. More, more.
Videography is Superb!
Cheers 73s
9V1KM KK7QGL
Kevin MAGNUS
Singapore
Ps. Could you A FT-991A begineer setup with an ATAS-120A please🎉
Happy Weekend into Orange County CA. Uncle Günter waving a Hand 💯🍻🙋♂
Waving back atcha! 🖐
Does anyone happen to have some ideas on why a fairly new Ameritron AL-811 amplifier doesn't show any change on the amp meters or a watt meeter when turning the plate?
I can't tune it since nothing happens with plate and puts out no power. Had the 811s and they looked fine but also switched them out with 572 and no change. Visual inspection inside I see nothing standing out and everything from outside seems fine. It shows the red transmit light when I key etc as well.
Ty
Where can get the keying cables
Hi Bill, Glenn N5JAI
He does ya e a great voice, ok to be clear on coax cable jumper placement or what have ya, so we go from radio in to amp, out of amp in to the meter, and out of the meter to the dummy load? Or antenna?
Most manual external tuners have meters built in, so the setup is:
Radio -> Amplifier -> Tuner -> Antenna
For tuners without meters:
Radio -> Amplifier -> SWR Meter -> Tuner -> Antenna
Always tune the antenna with the amplifier in bypass mode. All equipment to the right of the amplifier in the flow charts above must be able to handle at least the maximum power of the amplifier, preferably more.
What do you do with the built in tuner in the radios?
What about an external antenna tuner?
How does that fit in?
The "tuner" in the transceiver is only designed to help match small mismatches between the 50-Ohm output of the radio and the antenna that's attached directly to it. When you use an amplifier, the antenna is not attached directly to the antenna anymore, it's attached to the amplifier. So, when you're using an amplifier, your antenna needs to be resonant, or you'll need an external antenna tuner. The amplifier expects to see 50-Ohms at its antenna output, therefore the tuner must be placed between the amplifier and the antenna. Before even activating the amplifier you have to use the transceiver and the external tuner so that the amplifier sees 50-Ohms. Then you activate the amplifier and do the process described in the video.
My exact same station, only difference is the dummy load
Question: Once I have tuned up my amp in the middle of a band. If I switch to another frequency at the bottom or top of the same band do I need to re-tune the amplifier or am I good within that entire band? Thanks and 73
Totally depends on your antenna. If it has a large bandwidth, then no, you wouldn't need to retune. But few antennas are low SWR across an entire band. Your antenna could be 5:1 at the bottom, 1.7:1 in the middle, and 4:1 at the top. If you tune it in the middle of the band, it will not be tuned at either the top or the bottom.
@@HamRadioOutlet That makes sense, doing some testing with amp on standby should answer my question.
Just passed my test i already want to run an amp after running 1k watts on my CB radio i just wanna feel the power on ham
Assuming you just passed your Technician test, you are limited to 200 watts on the HF bands.
Niceeee video
Question, where would I place the tuner in this mix?
Between the tuner and antenna?
Thanku
Bill
The amplifier must see a 50-Ohm load... which means your antenna must be tuned to 50-Ohms. This means the flowchart goes...
Radio -> Amplifier -> External Tuner -> Antenna
It also implies that the external tuner must be able to handle the power of the amplifier as the amplified power will be going through the tuner whenever the amplifier is running. You can't use the tuner built into the radio as that would simply match the radio to the input of the amplifier, which is always 50-Ohms and therefore 1:1 SWR. Meanwhile, the amplifier's output is attached to the antenna, whose SWR could be significantly different.
To tune the antenna, you would put the amplifier on bypass (so it's not amplifying anything), use your radio to output a constant carrier and use your external tuner to match the antenna to 50-Ohms (as close to SWR 1:1 as possible). Then follow the instruction in the video for the amplifier.
@@HamRadioOutlet
Thanku so much!!
I meant: Where would I place an external watt/swr meter?
Thanku
William
@@WILLIAMPERRELLIYou have to think "What am I measuring, and why?" This makes the solution to your question obvious... What does an SWR/Watt meter measure? It measures the SWR between the transmitter system and the antenna system. The transmitter system is everything dealing with creating and amplifying RF. The antenna system is everything dealing with the antenna and matching network.
Since all modern transceivers and amplifiers output 50-Ohms and expect a 50-Ohm input, placing a tuner or SWR/Watt meter between the transceiver and amplifier would always show 1:1 SWR. It would also show the power as whatever the transceiver was outputting... both of which are pointless since you want to know the SWR of the antenna and how much power is going to your antenna from the amplifier.
Most external tuners have built-in SWR and Watt meters... that's how you measure SWR! Power going out vs reflected power. The tuner will show you both output and reflected power, and SWR (either digitally, on a single needle, or using crossed needles). So nothing changes from the previous description.
Take a look at the MFJ-976 external tuner: www.hamradio.com/detail.cfm?pid=H0-007445. See the meter? That shows everything you need to know. No need for an external SWR/Watt meter! Same for the LDG-1000Pro: www.hamradio.com/detail.cfm?pid=H0-011524, or the Palstar HF Auto: www.hamradio.com/detail.cfm?pid=H0-011436.
If your tuner has no indication of SWR or power out, then the SWR/Watt meter would go between the transmitter system and the antenna system... that is, between the amplifier and the tuner:
Transceiver -> Amplifier -> SWR/Watt Meter - > Tuner -> Antenna
Reading from right to left... the tuner adjusts the match of the antenna, which is displayed on the SWR meter and provides a 50-Ohm load to the Amplifier.
reading from left to right... the transceiver supplies RF to the amplifier, and the watt meter displays the output power.
The SWR/Watt Meter and the Tuner must be rated to handle more than the maximum output power of the amplifier.
@@HamRadioOutlet Got it!!
Icom-7300, to a Hkit sb-2060a tuner, to a Hkit sb-1000 amp and out to an end fed 80-10.
@@HamRadioOutlet The reason I wanted to add another watt meter, is to verify the meters on the Hkit s2060a’s.
Thanku and I appreciate ur help!!
Billy
Place sure look naked with no antenna on top of the building
There are antennas! You just can't see them (they're wire antennas)!