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Author Topic: What to expect with ALS-600 ?  (Read 14425 times)
VE3PP
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« Reply #30 on: January 25, 2011, 09:03:15 AM »

In the ideal world we would all have 120 foot towers, 4 of them. We'd have mono band yagis to cover the bands from 40 meters up. We'd have full wave delta loops hanging off those towers to cover 160 and 80 meters.

All fed with hardline of course for low loss.

However we do not all live in that ideal amateur world. Some of live on city lots with hydro feed lines crossing back yards (my situation).  

We can not put up 40-60 foot towers as they would need to be installed on property lines, close to neighbors homes. We'd have to put beams on those towers, that would hang over our neighbors property. This would lead to issues with neighbors (Been there, done that)

So some of us live with less than ideal antenna farms. Low dipoles, if we are lucky we can hang up a fan dipole or single band dipoles.

Some are not that lucky, they can only haul up one antenna to cover as many bands as possible.

So up goes the G5RV. Or a windom or OCF. We have all read the arguments when it comes to the performance of the G5RV. That antenna's performance has been beaten to death over the years.

However at the present time that is all you can put up. So you make due with that antenna.

All the experts scream "Improve your antennas before buying an amp" And yes I do agree with that statement. However, not all of us can improve our antennas beyond what we have up already.

So we buy an amp. After all you can hear those DX stations, they just can not hear you.  Angry

I do agree with the statement that going from 100 to 500-600 watts makes a huge difference to the receiving station. Going from 600 to 1000, not so much.

So I say buy the amp. I have two of them here, both tube amps. Al-80A and SB-200.

They make the difference between making that one contact you need or not making it. Even with my less than ideal antennas.

Of course if you can not hear them you will not work them even with 1500 watts.

So now you decide which amp to buy. The idea of the 600 watt no tune amp appeals to me too. But the cost doesn't appeal to me.

Tube amps are good pieces of equipment to own if they are in good condition. They become easy to tune once you use them for awhile. I can quickly tune the AL-80A when changing bands.

You want the LDG 1000At Pro tuner. I own the earlier model and I enjoy having it. But again, if you have a good manual tuner you can change bands and tune quickly. Simply make a chart for your tuner settings and have it in front of you.

Change bands, tune the tuner as close as you can to the settings you have on the chart. Then quickly tweak it with a carrier.

Tune your tube amp into the dummy load then tweak it into the antenna.

Simply and easy.

But if you have your heart set on that ALS-600 then go buy it. If you can afford it then buy it if you want it. Same goes for the tuner.

One thing I would suggest, if possible. Put up mono band dipoles for the bands you want to operate the most. Better performance than the G5RV. Especially on 17 to 10 meters. Or possibly a ground mounted or roof mounted vertical for those bands.

Of course that is if you have the means and space to do so.  Like you I have used the G5RV in the past. It did what it was designed to do and nothing more. I had terrible performance on the higher bands, from 17 up. It was ok on 80 and worked well on 40 and 20. 30 meters it was a dead horse!

Please remember folks, not all of us can have a Super Station when it comes to antennas. But we can construct the best possible station below the antennas. So please do not go on and on about improving antennas. As I said not all of us are in the situation to do that at our present QTH.

In the future if you can put up those towers and yagis you will have the station below it all ready to go.  Smiley
« Last Edit: January 25, 2011, 09:08:37 AM by VE3FMC » Logged
N4KC
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« Reply #31 on: January 25, 2011, 12:57:24 PM »

For goodness sakes, buy the amp!  And do what you can do with the antenna.  I was a ham for 42 years before I added an amplifier and still run probably 85% of the time barefoot.  Sure is nice to reach over and turn on that powerful, pulsating trio of 811s when I need them, though.  And it does make a difference.

For antennas, the hexbeam can be quite stealthy.  See my article at http://www.eham.net/articles/20575 or at www.n4kc.com, including pictures that show my house with no antenna visible.  A dipole as high as you can hang it, cut for the lowest band you anticipate working, fed with ladderline, is a good low-band antenna and backup for the other bands.  The auto-tuner will match it fine in most places.

PS: the amp is an Ameritron 811 and I use the MFJ-998 auto-tuner.  They work very well.  Either the ALS-600 or Tokyo Hi Power 750W amp is in my future...when my ship comes in.

73, and see you "on the wind."

Don N4KC
www.n4kc.com
www.donkeith.com
http://n4kc.blogspot.com
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W6GX
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« Reply #32 on: January 26, 2011, 08:09:45 PM »

I'm runnng a 600w THP amp, MFJ-998 tuner, and a two-element Mosley beam.  I love this setup.  Yes I do have covenants here.  However the antenna is mounted on my roof and it's in the back of the house, so it's not visible unless you're looking for it.  Like ES1TU said life is too short to not run a beam and go QRO.

73,
Jonathan W6GX
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KG8JF
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« Reply #33 on: January 27, 2011, 04:54:49 AM »

I own and use daily, an ALS-600.  I bust my share of pile-ups, but I am no match for a guy with a good beam antenna and 1500 watts.  Here are my sentiments, if I can't be heard with 600 watts, I can't be heard with 1500 watts.  That works most of the time.  And yes, I am very happy with my ALS-600.
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KD8PGB
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« Reply #34 on: February 01, 2011, 02:05:51 PM »


 Thanks for all of the responses guys, after reading all that I can here and talking on the air with some local elmers, I'm leaning toward an AL-811H, I know the AL-600 is easy to use but I will learn a lot more and become a better ham by having an amp that requires a little tuning . Not to mention the tube amps are bit more forgiving for new hams Smiley


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KJ1D
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« Reply #35 on: February 01, 2011, 05:00:22 PM »

I think you will be happy with the 811H. I have one and it has performed very well. I don't drive it very hard. Usually about 600 - 650 watts out. You do have to tune it but that is part of the fun. Let us know how it goes.
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KH6AQ
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« Reply #36 on: February 02, 2011, 08:11:14 AM »

The AL-811H is a good amp. Be prepared for a tube failure or two in the first year.
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W4PGM
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« Reply #37 on: February 02, 2011, 09:16:27 AM »

Expect 400 Watts.  (Yes I have read the 600 Watt posts)  The MRF-150 TMOS FETs is rated at 150 Watts and there are four in the 600.  In my opinion, the design is short on cooling if you want to push the FETs to their max.  I owned the ALS-600 for about two years and only had one issue with a $0.50 transistor in the SWR circuit.  It is a good amp, but do not over drive it.  If you see 600 Watts out, in my opinion, you will be sending it in for new finals.  Also, remember that the difference between 400 watts and 600 watts is 2db, no even a half a S unit.   


Tube amps are not that daunting and there are very good buys on amps that will give you a true 600-800 watts.  It is not that I do not like the 600 it is that there are other options if you do not require solid state.  If you do require solid state compare the Tokyo Hi-power Amps to  the Ameritron equipment you will find a much better built as well as  engineered design.   Used the THP amps can be bought for less than or about the same as a new ALS-600.
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KH6AQ
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« Reply #38 on: February 02, 2011, 10:55:00 AM »

Dropping the ALS-600 from 600 watts to 400 watts does not reduce MOSFET power dissipation.

The key-down power dissipation is reduced from 600 to 580 watts when the RF output power is reduced from 600 to 400 watts. That is for a constant drain voltage. But the drain voltage rises (in the linear power supply version) at lower power (lower current) resulting in INCREASED power dissipation at 400 watts. The ALS-600 RF input power should be increased until the amp begins to saturate. Do not drive it harder. Saturation is indicated by the power output starting to increase more slowly. For example:

40 W input, 400 W output
50 W input, 500 W
60 W input, 550 W   it is beginning to saturate
70 W input, 575 W
80 W input, 585 W

The ALS600 has a fixed impedance transformation ratio and so the DC-RF efficiency drops as power output is decreased.

Example: DC power in 1200 watts, RF power out 600 watts, MOSFET dissipation 600 watts
               DC power in 1000 watts, RF power out 400 watts, MOSFET dissipation 600 watts

To reduce the power dissipation the ALS-600 linear power supply has a switch for RTTY mode. In that mode the supply voltage drops from 50+ volts to 42 volts. The amp is now an efficiency 350 watt amp.

A tube amp having a variable output matching network is different. It does not have a fixed impedance transformation ratio and can be adjusted (within reason) to maintain efficiency at reduced output power.

So what do you get if you reduce the ALS-600 output from 600 to 400 watts? MOSFET current is reduced by 1/5. MOSFET peak voltage is reduced by 1/5. MOSFET power dissipation is not changed. The 1.8 dB reduction in signal is important and can often be the difference between Huh and a QSO when working near the noise level.
« Last Edit: February 02, 2011, 03:52:27 PM by WX7G » Logged
WA9RHD
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« Reply #39 on: February 02, 2011, 07:10:04 PM »

I have had the ALS-600 for a few years and I can tell you it does make a difference.

I wasn't even sure I needed a linear but at the margin it makes the difference, especially with the great band conditions we usually have. I have gotten through all the pileups I have the patience to sit through. When I call CQ sometimes I start barefoot and then if I get no response I kick in the amp - that usually makes the difference. 2 S units may make the difference between a QSO and talking to yourself.

My decision was that I wanted an amp that works on 120VAC not 240 and was solid state - not wanting to have to tune it and worry about tube life, availabilty and so on. If you have an antenna with a low SWR and can manage to remember to turn the bandswitch its a nice addition to the schack. I also use my antenna tuner to match the linear to get the most out of the modest power increase. You don't need anymore power than the 500-600 watts unless you want to waste your money on a legal limit or near legal limit amp. But there is no substitute for a good beam antenna. I use a hexbeam on 20M-10M and a dipole below that - the extra power helps on 40 and 80 but can't make up for a marginal antenna.

My concern would be the quality of the Ameritron amps - I have had an intermittant keying problem since I got it - so beware.



73's
Jeff  WA9RHD

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K6AER
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« Reply #40 on: February 02, 2011, 08:44:36 PM »

There is a corollary to the old saying, ”if you can’t hear them you can’t work them”.

“If they can’t hear you they won’t call you.”

This is especially true of DX. I know everyone get a bluebird every now and then but an amplifier to DXing is what horse power is to racing.

I always call CQ with the amp on at 1500 watts. After making the contact I might reduce power. I have found most hams have anywhere from a S3 noise level (quiet in a suburban neighborhood) to over S9 in many cases.

For those with amplifiers call CQ at 100 watts and make a note of the reply’s you get. Then call CQ at full legal power and note the reply’s. I typically see 3 to 4 times the reply’s. In many cases the ham replying back has a poor antenna and lives in a very noisy neighborhood. There is nothing he can do to improve his situation. Because you are running power he is able to have a nice QSO where otherwise he would have a struggle to have arm chair copy.

You can always reduce power but if they can’t hear you, you might think the band is dead.
« Last Edit: February 02, 2011, 08:50:46 PM by K6AER » Logged
AI4HO
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« Reply #41 on: February 04, 2011, 10:13:19 PM »

Daniel,

I have had my ALS-600 almost 2 years now, I am using an FT-450 as the exciter  and typically run about 35-45 watts to get the rated 500-600 watts out.  I have  G5RV, a home brew half wave 40 meter dipole, a Mosley TA-44 on an old HyGain 52' crank up tower, and a GAP Challenger vertical, I am also using an LDG AT-600Pro, mostly as an antenna switch for my FT-450 station which is in my living room.  The AT-600Pro is and was built with the ALS-600 and other medium power amplifiers in mind.  If you have no intention of getting a higher powered amp then I would suggest getting the AT-600 Pro,(current price at www.cheapham.com is $305, which is where I got mine.).  On the other hand, if at some point in time and you get the urge and intend om getting a higher power amp, then by all means get the AT-100Pro, wither one they are both great tuners.  My AT-600 tunes my G5RV in nothing flat.

My other station, which is for all intents and purposes is my main shack, I have an Icom 756 Pro III, an Ameritron AL-811H, a Palstar AT2K tuner, rotater controls, and a Diawa 2 position antenna switch, which I am able to switch from my dipole to my beam which all leads to the fron room.  All it takes is a couple of seconds to take and run my jumper from the Pro II to the antenna switch and I can operate all but my vertical on the Pro III, I have it this way intentionally, just want to keep the vertical for my Lazy Boy HF Station ;-}

I will agree with the many posts that encourage you to....when you can that is, better your antenna system.  My Mosley 3 ele tri band beam is every bit of 40 years old, the only thing I needed was a new 20 meter trap $60 and 3 months later I finally received it.  That's not the point, I paid $100 for my beam, I used and still use a vertical, I started with a GAP Challenger, went to a GAP Titan, had to sell it when the tower went up as I didn't have room for it and the tower both.  Our pool and subsequent enclosure saw to that.  I have had a couple of different verticals both Hustlers a 4BTV and a 6BTV, great antennas, never got around to putting down any radials for it just used as is, made contacts with it.  Sold them was finally able to go to GAP Antennas and get another Challenger, home brewed 3 radials for it,(which that is all it calls for is 3 radials, mine are about 21' in length).  I am always switching from one antenna to another, I may not always use the amp, but its there, like one post stated, its a tool, that is used, its a very useful tool, but  tool never the less.

Its a pain at times when I'm on the Pro III using the AL-811H and my manual tuner for my G5RV, yea the Palstar is a very nice tuner it is quite smooth and takes almost no effort to tune my G5RV, but the LDG AT-600Pro is quick and decisive, I switch to CW, with 45 watts, hit my key and my G5RV is tuned, almost that fast.  Get the ALs-600, and the AT-1000Pro or the AT-600Pro and have a blast!  Have a great weekend..


73 de Mark
W3LZK
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