Ameritron ALS-500M Amp and MFJ-4275MV Power Supply

Dave gets an amp! I've mentioned it incidentally, but here's a whole video on the HF amp and its power supply. Even though it's many years old, it's performing reliably and consistently. Subscribe: / @davecasler Ask Dave Playlist: goo.gl/inaQeB. Tip Jar: ke0og.net/tip-jar
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[@nz0z134]

I can't believe this amp has been around almost as long as the internet and this is the only decent review online

[@kb7uxe]

Thank you for the great overview and unbiased opinions. very complete. thank you.

[@KB5PQL]

Great video! I recently bought an ALS-600 and I’m also very pleased with it. ☺️. I never owned an amp either in my 25 year ham career. 73!

[@kevpeacock5673]

Thanks for the review Dave. I have been contemplating buying an ALS-500m to take out bush with me for field day contesting, plus being able to use it at the home station when not away, with 400PEP max. here in Australia it seemed like a good option. The only feature I do not like is the band switch. With that in mind I did search for similar small mobile amplifiers and found there is in fact a huge number available. Prices comparable to new ALS-500M and not requiring band switching. I ended up buying one that was manufactured in Italy (not Taiwan). More compact, external heat sinking, no band switch and no meters. Activated by RF no PTT connection. I piggy backed two 40Amp 13.8v power supplies and it cruises at the legal limit. Out bush I run the amplifier and other equipment on 3 x 120amp AGM batteries using a little Yamaha generator to keep them topped up. Learned quickly to keep the contacts short hi hi. RST, Grid Square, name and 73's. And yes the little bit of extra outgoing power works a treat. Hope to say g'day on air sometime. 73. de Kev VK4ZY

[@robertlackey9742]

Thanks for sharing your new Roy's with us . Especially the inside view. That's some pretty work. 73's and enjoy. RJL

[@brucebolton5115]

Just bought the power supply at HamCation in Orlando, great video Thanks KW4FH

[@96GQ]

I bought one of these amps a few years back after it was for sale on QRZ, fortunately the Aus $ was above parity so the cost was acceptable. It's a great little amp and does the VK- 400w max quite easily, though I did have to buy a Manson 120Amp Power supply to make sure it had enough juice to run. I put the 10m Mod in mine which was easy to do and when conditions improve I might do the 12m mod as well. I recommend the amp for sure and thanks for the interesting video Tom.

[@Laborkei]

I use this combination as a backup amplifier at home. My 500M is old like the one you have here in your video, it was never mobile. I purchased it to run with my Icom 706MKIIG, but I didn't want to install the infrastructure in my vehicle for the amp to work correctly mobile. I have the power supply plugged in to a 240V Circuit. Your right, you dim the lights if you use regular 120V Circuit.

[@darrellcollins877]

im 100 watts and a wire here , hope to talk to you on the air someday Dave. I watched some of your videos to help me gain my general license and now I am VHF and HF shack ready, 73 and congrats on your first amp !

[@Laborkei]

Thanks for the Video. I had an ALS-500M in a closet for years. Bought it new, never installed it since the vehicle at the time was wrecked later. I was particularly interested in the power supply which is where I found your Review. I just purchased one this week, the 220V Input version. They no longer provide a switch on the rear like yours. Now you have to choose 110V or 220V which does not make sense. But a call to MFJ talking to a Tech, they said they can tell me how to rewire it to do either. Go Figure... Why complicate things, as I wanted to run the Power Supply in my home on 220V, but when I moved to a different location, have the ability to run it on 110V. So now I have to do a re-wire job. My hope in the future is to make up two computer power cables. One for each voltage and put my own switch in the rear. But I will wait until after the Warranty is out on the Power Supply. I was going to by the Astron 70M, but it won't switch either. So there is something going on now to make everyone's life difficult with the inputs.

[@graywolf1911]

Hi Dave, when you keyed your Mike with your new (old) PA, the high Tension wires behind my house started to glow, and Niagara Falls power station reported a small overload on the system out west..LOL Thanks for another great D&P show, I really enjoyed the demo and the new PS is really nice. I have been watching the classifieds for a good deal, and one day I hope to find a PA also. Thanks again Dave. And BTW, I hear the snow is so deep out there in the Rockies this year that they actually cannot measure the depth because glacier ice is forming on the lowest levels !! WOW Modern day glaciers in the age of Global Warming ! Hope you don't get flooded out this Spring with the thaw.

[@daveN2MXX]

Videos like this are really great. I wish you made more videos like this in 2023.

[@ramonfuentescruz8647]

I really enjoy your videos, thanks for you time making them, Raymond, kp4kji, from Puerto Rico.... kp4 Island!!

[@Etherionix]

Congrats, thanks for the video. Enjoy.

[@davep6977]

Here's a little tech tip. I bought ALS 500 non functional off of eBay. It's 100% functional now and I love it, great amp. Ameritron tech support is great. The little board right behind the power connector is the combiner board. The little potentiometer sets the trip level. Be careful but you can set it from 1.2:1 all the way past 2.5:1 swr. Just remember the higher it's set, the more you are endangering the finals

[@DucatiMTS1200]

What a strange coincidence and summing up Dave of the exact issues and identical solution I am planning to implement to resolve link distance. In fact originally I was going to trade my DX3000 in for a more powerful transceiver but the cost was prohibitive and I do like my DX 3000. Funny I have become attached to my radio gear but yet I chop and change my motorcycles like there is no tomorrow. I have yet to cross the Atlantic from Ireland on 40m SSB phono but once I up the 100W to 400W and get an antenna with some gain I’ll call into my country cousins. Thank you for a great video and common sense narrative. (GI8WFA) / 73’s.

[@reallybadaim118]

This is a nice amp and power supply. Lucky you.

[@GlennGuillorySFO]

I got one of these, and the power supply. It took me 40 years also. Thanks for opening up the cons, so I don[t have to. I had to see inside. I am afraid to install it. I need a video from you on how to install it and operate it on camera if you can. God bless you and your sweet XYL.

[@panquilinares]

I Love my ALS-500. I use it at home with the MFJ 75 amp PS. On the go I hook it up directly to my truck battery with #6 wire jumpers. I use home brew EFHW resonant antennas with great results. 40mt and 20mt no tuner. TKS 73’s HP3FL

[@michaelwright1001]

Great story and a great video. Thanks.

[@DavidGillooly]

Super review and food for thought. I have a pretty poor QTH for receiving. Hearing is my problem! I have never had anything more than 100W. Antenna for decades was an old AEA ISO-Loop 100W TX/RX ground mounted loop, Butternut vertical (HOA had to take down), and now Buddipole vertical. I am looking forward to having a new QTH in a few years and started thinking about what a shack would look like. Definitely would like a tower and beam plus a few wire dipoles for the 40/80M bands. A power amp would be nice and the 500 W range seems to be a nice power point.A full kilowatt would only give me q 1/2 S-unit advantage at significant price increase. The no-tune feature of the ALS-500 is intruguing to me. Plus at $949 and the MFJ-4275MV price is pretty reasonable at $259 too. Note that MFJ also has an automatic bandswitch box for $119. I have also looked at the Ameritron AL-811H tube amplifier (600W CW (my main mode), 800W PEP) for $999. Not auto tune though so not as convenient but the power supply is built in so a bit less costly overall. You are right about the antenna tuner. I have a external one but it is only a 100 W one. I use the TS590S internal tuner right now as it works fine. Having a good SWR on the antenna makes it easier!

[@f.allenrisler5303]

At max power, how much current did the power supply draw from the electrical outlet? Is a larger circuit breaker required to run the radio and this amp/power supply combo?

[@foxfirevalleyvineyrd]

Love to see a video on how you hooked up the MFJ 4275 to the ALS 500. I had no trouble hooking up my ALS 600 to it's power but this ALS 500 is causing me a bit of grief.

[@billkc2tux211]

Excellent video, thank you!

[@DonDegidio]

Dave, Nice video. I've gotten back into the hobby after a 25 or so year lapse. Had fun during the contest this past weekend. I have a Wilson TT45 crankup tubular tower that was refurbished this past summer. Still need to rehab the T2X rotator, but it is functioning. The tower was topped with a Tet 3F37DX tribander that has 3 elements on 20 and 5 each on 15 and 10. I have refurbished both the two directors and reflectors. Only need to finish the three driven elements. Wish I had that antenna operational for the contest. Was using an FT-450 for the contacts at 100W. I also have an SB-221 with the 10m mod from Heathkit, but it is currently in storage. The health of my 91 year old father had taken a downturn, but he is on the mend. That's one reason for not having the yagi finished. Hopefully I will have it done by months end. In the meantime, I have made a rotatable dipole out of a pair of Hustler MO2 mobile masts and the tri-resonator accessory and resonators for 80, 40, and 20m. That was the antenna used during the contest. I was pleasantly surprised that with this shortened dipole was able to make contacts to Europe, Caribbean, and South America. I also have a 4 element 6m yagi going on the tower. 73 WB3BJU

[@davecasler]

Sounds like you're getting back in the swing of things. My dad is also 91, with a birthday coming up next month. Good luck with the antenna work! 73, Dave

[@billashby2156]

Dave, A few years ago, I came across a local HAM who had an Ameritron AL-80A, which he had Never applied Power to! I picked it up for about 30% of what a New Amp would’ve cost, and took it home, applied Power and left it on for the recommended 10+ Hours so that the components/Tube could “Outgas”. With 110vac applied to the Amp, I was consistently getting between 7 00->750 Watts output! I’ve read some of the Spec’s, and if/when I have a 220vac Line available (which I Intend to have Shortly) I Should be able to get 1kw+ Out! I’ll let you know after I’ve been able to accommodate the Amp with the 220vac line as to How Many Watts I actually get out of the Back-end of the Amp, but in Any Case, I’ve found the Amp to be Reliable Without raising my Grid Power Bill to Skyrocket! I Would, and Have recommended this Variety Amp to both New And Older HAMS who Want/Need some “Extra Power” to be able to reach those Far-Off Stations!

[@windwrightmage]

Excellent video. I'm strongly considering this power supply for ham / CB Radio will use it to run a 600 to 700 watt linear amplifier. how well will this power supply run this I don't want to Max it out or make it run too hot

[@dougarcher3631]

Where did you connect the separate line for 14-16 Vdc at 4 amperes for control and bias circuits?

[@PatriotPaulUSA]

That good old american made stuff had so much overload factor designed in I wouldn't even think about it being 5 amps less. What a great find! Your friend likes you! :) or he was really needing money :)

[@gregmahoney9116]

Im wondering I have the same amp and a new mfj 4275 power supply , two questions.. the fan on the power supply cycles about every 5 seconds without load ! when keying the mike how many amps should show on the meter ? plus I've not heard the fan on the amp come on ever , I'm using my ic7300 driving 60 watts

[@pauljohnson9566]

Do all red wires go to the white connector on the front of the power supply?

[@bobclarie]

Very nice Dave. I'd love to have an amp, however, I'm stuck in an HOA operating situation. My transmit antennas are dipoles in the attic, and my receive antenna is a Pixel, receive only mag loop outside on a rotator; It's disguised as a bird feeder holder. Despite the CC&R's, I still enjoy this great hobby. Thanks for sharing your experiences and knowledge. Bob '73 N7ISU

[@davep6977]

I have almost the same set up. I use a linear power supply (Astron 35M) for my gear and the switching supply for my linear. Sounds funny but it works. My only dilemma is the battery back up is a nice feature but my amp gets it. I thinking of a switch that I can connect my radio's to switching, but I haven't solved the issue if the power comes back on, my switching supply is at 16 vdc

[@davecasler]

Yep, you don't want to feed 16v to your transceiver.

[@patrickbuick5459]

Thanks Dave. Just what I needed to know when considering "more power ugh ugh" (Tm Tim the tool man Taylor)

[@RobPetty622]

If I were to run this portable in a park, not mobile in the car, what size LiFEPO4 batter would be required to operate the power supply? 75 amps? Likely not something I’d do due to size.

[@davidhtims]

David, I’m not sure you will read this but here goes. I found a ALS 500 on eBay recently. It came with a 75 watt ps that looks just like your MFJ but a different manufacturer. when I connected it up the ps it made a LOT of noise on some bands.

[@dennyoconnor8680]

Dave, if you still have the amp protect those Toshiba transistors like the Crown Jewels of England. They are unobtainium now and the chinesium ones are limp noodles at best. In January of this year (22) half of my chinesium transistors on my brand new ALS-500 were bad right out of the factory sealed box straight from Ameritron. The factory replaced them with more chinesium and I have not put power to it since the return. Once bit, twice shy.

[@greghubbard2598]

Are my eyes tricking me or do you have a black wire running to the positive (white) 75A terminal? I see the two reds and one black but shouldn't it be 3 red wires connected to positive?

[@policyprogrammer]

I'm two years into the hobby with 100W and a couple of dipoles in a tree. I think I, too, will wait 40 years to get an amp. Though, I'll admit, it was a bit frustrating this weekend to hear all these stations of exotic places and not get them to call me back....

[@marklowe7431]

The contact you have made a probably more of an achievement to be proud of as apposed to running kw's of juice that makes the sky glow. At one stage I ran 10w and a 2 ele quad and it made the world very small. Recently it's loops and must say i would find it hard to go to a any dipole now.

[@Porco_Utah]

I used to have HF radio use two of 2SC2978 transistor final , by adjusting ALC, and adding 14V DC or so, I was able to put out 300 watts on 1.8, 3.5 MHz, I only used for CW , so I was not concerned about linearity / IMD of amp. 300 watts of CW was enough for me. AG6JU

[@Outdoors_with_kg4muk_Wayne]

I was going to put a on off switch on front of power supply that powers my ftdx101 and Kenwood 570 but lighting hit my house last Wednesday and took out $14,800 in Hamradio loss so I’m not on the air anymore now but I did like my power supply

[@paudelei]

Thanks David for your vídeo. Pleasae, would be kind to tell me ehen operating what do you use between the Radio TX, the Amplifier and the antena. Thnks and 73 CT1ADM Jorge

[@davecasler]

I use LMR400 cable except for one short piece of RG-8X for the amp. I don't have a high power tuner, so I must keep my antennas tuned.

[@paudelei]

@@davecasler thanks dear David. To have the antenna tuned is the most important. All the best to you. 73

[@glenmartin2437]

What protection circuits does the mfj power supply have to keep it from going over voltage ? Glen, N0QFT

[@davecasler]

There isn't any mentioned in the manual, so I don't know. Sorry.

[@davep6977]

the smoke detector in the ham shack lol.

[@philipchandler330]

Enjoyed the video so what mid power Ameritron Amplifier would you recommend for use with ICOM 7300? Any addition equipment as well would be helpful too!!

[@davecasler]

Wow...amplifiers, like radios, are a highly personal choice. Call Ameritron and discuss it with them.

[@davep6977]

The amp doesn't care where it get's it drive from. Almost any amp will work with any radio as long as your antenna, feed line and any after the amp is rated for the power

[@popsinabox]

Can the power supply support both your 100w radio AND the ALS-500M or would I need a separate power supply?

[@davecasler]

No, you have to use another power supply. The 100 watt radio takes an additional 20 amps.

[@MichaelLloyd]

I always enjoy your videos, this was no exception. 73 NE5U Mike

[@davecasler]

Thank you!

[@johnwmacdonald994]

Hi Dave. I've been interested in one of these since I saw one for sale on qrz.com, so It's helpful that you could review one for us. I've not been too interested in amps because I can't scale up my home power nor my wire antennas very easily. And of course they cost big money. But something in the 500W range would make some sense, assuming not many changes, though I'd still need another electrical circuit I imagine. So maybe one will fall in my lap some day and I'll give it a try. Thanks for another great video. All the best, John, KC1DIW.

[@joeblow8593]

I saw that it can run on 240 volts, maybe if you run it on 240 volts that might take care of the lights blinking when using it. Nice amp by the way...

[@daviswallace6351]

Dave...I have the same equipment that you do: FTdx-3000, ALS 500m, MFJ-4775 P/S....along with a MFJ 994 tuner. I would like to see how you've connected everything together....especially how you connected the ALS 500 to it's power supply. What did you do with the rest of the 4775 power supply wires?

[@davecasler]

The MFJ-4775 power supply powers only the amplifier. I run very heavy cables from the power supply straight to the amplifier with fuses. The cables are very heavy wire and less than 3 feet long. I wish the heavy duty output on the MFJ-4775 were on the back of the unit, instead of the front, as that would make for a much shorter cable run. But what I have now seems satisfactory, and I get about 600 watts indicated output at 16 VDC. (The manual says the amp works fine up to 16 volts.)

[@daviswallace6351]

David Casler did you replace the Jones connector on the ALS-500? If so, could you tell me what you replaced it with. I won't ever install the amp in a vehicle, and would like not to have to mess with the Jones connector with it myriad wires. Thanks for all your help

[@daviswallace6351]

I have a friend who is a EE that will help me with the Jones connector issue. However, another challenge that faces me: I have the ASL-500RC remote head and ARI-500, but have decided they are not applicable for a shack installation and operation. So I am left trying to figure out what wiring is really necessary...A picture of the rear connections of your set up would really help....(beg, beg, beg)

[@georgeknapp4909]

My antenna is only 6 feet from transceiver . Good or bad.

[@davecasler]

Depends on your power. If you're running 5w QRP, no issue. If more, check my video on RF safety for more information.

[@thormusique]

Excellent video, thank you! I'm unfamiliar with working with amplifiers, so I'm wondering: Can you still control power output from your transceiver with the amplifier connected, or is the amount of power output fixed by the amplifier?

[@davecasler]

There is no ALC feedback from the amp to the transmitter, so you have to control power from the transmitter end. I find that 62 watts indicated gives me full power out of the amp.

[@thormusique]

Excellent, thanks!

[@georgeknapp4909]

Appropriate for 955 Stryker on the porch and how much for the als-500 amp and power supply. Km4ypd

[@davecasler]

The amp is on ameritron.com and the power supply at mfjenterprises.com.

[@jonfleurichamp5323]

Newer ALS 500 may have rft pp100 transistor.

[@richardkolacki6648]

hey dave nice m500 amp can u run this 500 on 120 outlet or do u need 220

[@davecasler]

I use 120. The lights do dim a bit.

[@MM0IMC]

I still prefer a linear PSU, as compared to a SMPS type - because of RFI (noise) issues.

[@sparky42]

Nice amp . I purchased a brand new Dentron GLA 1000 back in the day . It has a pair of D-50 ( 6LQ6) sweep tubes in it and puts out less than 500 watts but I love it . I used it pretty hard in the 80's and 90's and it still has the same tubes in it !! Anyway I do not operate much QRO ssb much anymore and like the challenge of QRP ( mainly CW ) now but once in a while I will run full barefoot power of 90 or 100 watts especially in this last cycle . I enjoy your videos ... de KA3FAD

[@monabecaoficial]

An ameritron als 500m like the one you are showing, do you know how much I can sell it used?

[@davecasler]

I paid only $200 for mine.

[@monabecaoficial]

@@davecasler thank you so much for the info!!! it helps a looooot!!!

[@AdamosDad]

I realize this is an older post but I still thought I'd ask Dave. I recently got the same amp from a silent key from our ARES club, I was under the impression that it is a 500 watt amp. you said 600, I am only realizing about 215 w. with a 20 watt driver. Will it run 600 watts?? I'm using a 100 amp PowerMax .🎙73's kd9oam

[@scottlitz3199]

Yep it will do 600 watts you need more drive from your transmit to get that. Much out of it ,mine needs about 65 watts to get there .73s-Kc0rom

[@AdamosDad]

@@scottlitz3199 Thanks Scott, then there is hope. 🎙73's kd9oam

[@scottlitz3199]

Yep, I have an Als500m and a Yaesu Ft897d ,depends how hard you push the amp. 73s-Kc0rom

[@rmccombs66]

I was hoping you would show it in operation. Let us see some jumping meters!

[@jamesvw769]

Want to see jumping meters ? Fire up your Galaxy Pluto and your Boomer 600 and just have fun watching your meters. Just please do it in a dummy load.

[@georgeknapp4909]

Hey Dave what wouil you suggest power amplifier or chamelion loop antenna looking to get the best bang for the buck.need help .remember me from on the porch operation.we are trying to improve all.is this better than the firesticke 5' .

[@georgeknapp4909]

Tip jar I am looking?

[@davecasler]

If you want to increase your power out, get an amp and be sure your antenna can handle it. The Chameleon antenna will only handle about 50 watts SSB, which means if you use one of the many 100 watt rigs, you'll have to throttle the power back.

[@davecasler]

www.ke0og.net/tip-jar

[@gunrightsfan]

Nice video keep up the great work. 73's KM6AZZ

[@ZAR66]

Isn't your Horizontal Loop a gain antenna?

[@davecasler]

Not really. Horizontal and vertical loops can get a bit of gain in certain directions, but not terribly predictably, plus they usually aren't designed to rotate. That said, if you space a couple vertical loops properly, they get some directionality.

[@captlarry-3525]

Dave those big toroids in the amplifier are part of the Chebychev output filter, nothing to do with the input.

[@williampeacock9473]

I am kinda of curious how much you had to give the older gentleman for the amplifier ? I would love to fall into a deal like you have. You are VERY LUCKY HAM on my income it would take along while for me to save UP for a amplifier like that one. Congrats on getting the Ameritron mobile amplifier.73 AE4OY William P. EM-81uf SOUTH EAST GEORGIA

[@thefreese1]

Nice Video. However , the low pass chebychev filter isn't there to match or tune the input of the amplifier board . It's actually on the output side after the amplifier board . And it's real function is to cutoff frequency for the band you are on and stop out of band harmonics.. example : if you were to key up on 7.200 MHz ... You could be heard on the 1st harmonic of 14.400 MHz . The Amplifier , in fact , could actually run ok with it not even inline .... But of course it wouldn't be a wise Idea. Although CB amplifier makers do this all the time and almost never filter the output ... It will also allow a flat topping signal cover adjacent frequencies ... Where as CBers tend to think the more frequencies the wipe out he better the amp is doing .. Congratulations on a good buy of a wonderfully designed , gorilla proof amp ..... p.s. I know this is an old thread , but the theory will never get old ...

[@francismcclaughry3794]

I have to amps and I have never hooked them up I have a tube amertrion six hundred watts. and I an old Dentron full legal limit. I don't have either hooked up. I run bare foot.

[@leonardoriccardi3196]

Very good video Tnx. 5AT109 from Venezuela

[@slaznum1]

I would imagine you are not using a standard 15A outlet

[@davecasler]

+slaznum1 Yes, I am. The power supply will also work on 220 vac.

[@timdbl7804]

Hi Dave, thanks for the revealing video, I've never looked inside my ALS-500M. I suggest that you back off your drive power a bit, though, if you are using SSB voice. From your comment towards the end, it sounds as if you are pushing the amplifier into compression, even saturation I.e. non-linearity, which will cause distortion and thus bad 3rd order IMD products = what we all coloquialy call "splatter". I suggest back off the drive by a couple of dB.

[@nagasainathkoduru9995]

Try to use BITX with AMP

[@ctscantechnologist]

That is a beast of a linear amplifier.

[@davecasler]

It's nice. All things considered, it's pretty small--certainly smaller than the power supply, though much longer. So far it works flawlessly.

[@adelarsen9776]

Dear Dave, You appear more happy than usual. Did you win the Lottery ? When I win the Lottery I am going to build a 50kw station and aim my antenna arrays at China. Happy DX Dave, Congrats on the amp and good health to you. :-)

[@davecasler]

Always happy! (sometimes +/- given I'm bipolar). I've had the amp a year, and finally decided to talk about it. I've really enjoyed it. I guess it shows! (That said, I'm still working with the BITX-40! There's a factor of a hundred (20 dB, or >3 S-units) between them.)

[@tf7274]

I dont get the ham vs. Cb thing...both groups are dying while fighting...both use illegal gear on all frequencies...

[@captlarry-3525]

we are taking up a collection to get you A TRIPOD..

[@ElektroLUDIKITS]

Just a little reminder : with 600W instead of the regular 100 Watts of your transceiver output, your signal will be improved by a tremendous 1.5 S-units on your correspondant S-meter. It is not even a « couple ». Not even 2 S-units! ;) It means that if you are S9 with 600 Watts, with "only" 100 Watts, you'll be "only" S7.5 ;)

[@davecasler]

There are pros and cons to amps, and I've never been much of an advocate for them. This one fell into my lap, and I have to admit it does make a difference when trying to get through DX pileups. But I also enjoy CW QRP.

[@WW5RM]

That is the theory but ive seen 500 Watts increase signal more than one S unit. Why? Inaccurate meter or band conditions? Not sure but when conditions are poor and or static crashes are covering up stations I normally hear I was glad they had it! Sometimes even one S unit is the difference between heard and not! I preach......antenna, antenna, antenna and is the building block base to a good station. But sometimes like during the bottom of the sun cycle and thunder storm static crashes covering up stations you normally talk to on 40M or 80M an extra 500watts is nice to have! WW5RM

[@VNV67]

Hey Dave, You make a great video but as a camera operator you need some practice. Made me dizzy when I was full screen. LOL 73's W4DRA

[@davecasler]

No, I need to use a tripod. I've never been able to hold a camera still even when I was young.

[@kevingary7018]

It's funny, but I can check in to a net, or answer someone's CQ, and people hear me, but hardly anyone hears my CQ. I'm running a 100W bare foot rig - I have a hard time coughing up 5 to 6 grand on a new amp & tuner while keeping the Mrs. happy at the same time.

[@ctscantechnologist]

That amp is worth a whole lot more than you paid for it simply because it has Toshibas 2879s.... 73s... KD5TRI

[@captlarry-3525]

I will say flat out that operating this amplifier directly into an antenna is an extremely risky thing to do. Allowing any swr above 1.2 is simply not something I would do. Why depend on protection circuits to compensate for a non-resonant antenna ? The cost and annoyance of replacing your finals will exceed the 50-75 cost of a used tuner.

[@beekeeper8474]

Big plug for only using 4 spades

[@tangoseal1]

I NEVER enjoyed the excuse that an amplifier doesn't help your receive as the excuse to not justify one. An amplifier is so that you can allow others to hear you better. People forget that half the battle of HAM radio is not just making your own station RX extremely well, it is ensuring that you are not making every station you work suffer to hear you. Also the age old "Antenna is 99% of the equation" while true, is no longer the case in the current solar minimum. You truly need good amounts of TX power along with a good antenna. I have incredible antenna setups at my station and there are just some days that no amount of antenna or power makes a difference. It is what it is. We need power during the minimum. Some hams even as far as 2021 right now today just will NOT let go of the glory days of solar maximum where a wet noodle dangling in a lake could work the world at 1 watt on even 10 meters. Those days are gone maybe for the rest of our natural lives.

[@JamesGMunn]

Be nice to your amp, those transistors are no longer made and are now hundreds of dollars each!

[@davecasler]

Thanks for the warning!

[@captlarry-3525]

Linear Amplifiers have a long history and their efficacy in general isn't really a point of debate. If you don't want one, don't get one. Ameritron has a pretty lousy reputation in my book, so I am looking forward with interest to seeing the guts of this one. I admit I want to not like it because of who made it.. but staying open minded..

[@davecasler]

So far, it has given me excellent service.

[@captlarry-3525]

@@davecasler yours shows a very clean P.A. circuit board... compare to the one I just bought. Interesting.

[@davecasler]

@@captlarry-3525 Mine is an earlier design that has several layout and capability differences. There is a kit available that would allow me to upgrade, but it costs more than the $200 I paid for the used amp!

[@SuperGolfcar]

T

[@brianwoodard233]

IT IS NOT SIN TO POWER UP ,

[@kc8653]

Amps are overrated. Good radio, good antenna at a good height. Most of the time if you can hear them you can work them.

[@davecasler]

Yes, true.

[@macp8854]

uf is MICROFARAD and NOT MILIFARAD..

[@davecasler]

Good catch.

[@DaveW6OOD]

Wooh, got dizzy. JK

[@philipacovington]

Good Lord, you need to get a tripod or gimble! Your videography is making me dizzy!

[@jimcrance9233]

Hold the camera still get sissy trying to watch

[@davecasler]

Wish I could hold it more still. I'm a one-man show; it would be nice to have someone I could rely on to handle the camera--someone with a steady hand.

[@clauslauridsen4373]

why are you chaking cant hardley se anything on pic

[@BEdmonson85]

That power supply looks like a pretty poor design, one should never if at all possible ever place electrolytic capacitors next to anything that gets hot.

[@davecasler]

Fortunately, the enormous heat sinks plus the two fans seem to keep things cool. The fan comes on when things get warm.

[@BEdmonson85]

That's good to know. I may have been a bit harsh with that comment. The power supply looks solid, it's just after repairing electronics for as long as I have, things like that jump out at me when I see them. If anyone has had one of these fail on them, I'd be interested to know what the failure mode was.

[@KillerNetDog]

I also noted how the heat sinks seemed to loose and flapping around when Dave touched them, seems they should be a little more solidly mounted to me.

[@BEdmonson85]

TX Rider, Yeah I noticed the same but didn't mention it 'cause I wasn't sure if they were supported by the top or not when ir was assembled. I mean it's a nice piece of kit, I just personally think it's way over priced for what it is (as are most things in this niche hobby). That's why I prefer to homebrew most of my equipment.

[@KillerNetDog]

Yeah same here, or cheap used equipment. My radio right now is an British army surplus PRC-320.

[@RedNeckSurgeyTech]

Dave I buried my rg8x cable to keep the rabbits from chewing it up. but it would not be overly difficult to dig up if I burnt my cable. but assuming my antenna has less then 2:1 swr across all band. My question is will 500 watts ruin my rg8x coax. melt it or burn it, Please answer if you have the time, Thanks love your channel 73 KX0ALT