AL-82 amp off line. Transformer bad. Test setup

[Opcom]

I wish fedex ground had such cheap "box" rates. I guess it is worth it to pay fedex gnd higher costs as in 10 years only one thing got broken (a crt - the guts came loose inside) and I have had bad luck with UPS and USPS. Other say fedex ground is no better than UPS or USPS.

When talking about shipping damage, one thing to bring up is labeling the customer applies to the carton. Who actually uses cautionary labels?

On each side and the on top of every fragile item are one "fragile" sticker and one "delicate instruments" sticker.

On each side is a "this side up" sticker.

That is 14 stickers on a large item. The stickers are about 3-4" size. Sometimes I put the fragile or "up" stickers on corners of a small box, only two needed plus the one on top. What do they cost? Maybe 10 cents each, I get them by the 500-roll from Uline where I buy the boxes. For the <$2 cost of this, things don't get broken as much. If a sticker will fit, it gets one.
 
Now whether or not it really means anything to the carrier I can't say, but the liberal use of warning labels  either helps the carrier employee decide to take a little extra care with the box, or, it is a kind of mysterious juju or talisman.

I also keep a few tip-n-tell around, but only use where the cost is justified.

Give 'em a try, maybe it'll improve results.
http://www.uline.com

[W1AEX]

Al, I would not even fool with Ameritron unless the amp is under warranty.  I'd instead get a higher current CCS rated transformer or get the stock one with what sounds like a high resistance short in the secondary, rewound.  

Actually Rob, the stock transformer is a brute and not a point of failure normally. The power supply delivers 3300 vdc @ 800 ma and is rated to deliver 1500 watts continuous carrier output for 30 minutes without breaking a sweat. The way the air flow is laid out, cool air is pulled through the power supply components (left side intake vent) and into the bottom of the PA chassis, up through the tube sockets and chimneys and out through the top vent. It works very well even with continuous carrier modes like AM or RTTY. That being said, I don't run much more than 250 watts of carrier when driving it with the Flex in the AM mode just to be sure there's enough headroom. Ameritron uses the same plate transformer with the 3CX1500 and 3CX1200 amps as well. I think Al just got unlucky with this one, but fortunately it's a warranty job, so it's one of those annoying adventures that really shouldn't happen to good people!

Rob W1AEX

[K6IC]

Hi Rob,

The top three Ameritron Amps -- AL-1500, AL-1200, & AL-82 all use the same major guts, except the tube,  tweak for the Fil XFMR and chimney/s.  The air is drawn across the HV filter caps/bleeder Rs,  and around the HV power XFMR,  so the PS gets a fair amount of air circulation.

The transformer in Al's photo looks very much like the Dahl transformer,  minus the red/silver label.

Have had positive experiences with Ameritron.

Sorry to hear about your problems,  Al,  but it is good that it is under warranty.  My AL-1200 has been a very solid amp for 11 years.  Save for the replacement cost of the Final tube (about $1300, now),  it is still a great amp.  GL, Vic

[Opcom]

UPS = United Parcel Smashers

USPS Flat Rate or FedEx for me, thanks.

All shippers use the "8 foot drop" criteria.  We have to get over it.

Pack accordingly, buy LOTS of insurance.  $1,000 is an amount that gets attention and your box might travel "first class".

I have shipped lots of things to many members on this forum and so far nothing has arrived in worse-than-shipped shape.

73DG

On youtube there are videos of how boxes are handled at UPS. They are literally dumped from a huge mechanical bin and they fall and tumble several feet down. UPS employees are unhappy lot -and there are videos of them intentionally mishandling and damaging customer property.

I got the box of stuff from you in good order via fedex. Thanks BTW.

[Dave K6XYZ]

Joe.....instead of using the expanded white foam that gets all over the place, I use the blue wall insulation foam that does not flake like that other stuff does. You can cut it easily with a box knife and line the walls, floor and top of the box. Make it fit real tight around the transformer and use filament tape around all sides of the box and horizontally as well.
I get it at Lowes.

[WZ1M]

Al: I didnt see you say if you had put an ac amp meter on the primary when you brought it up on the variac. In most cases this will tell the story. Another test would be to split the primary and see what you get for hv at about 50 volts on the primary. Now put the 50 volts on the other side primary and read the hv. Is the hv the same as the first test, if not, you have a bad primary. If its the same then the secondary miite be bad. One other thing, never NEVER NEVER ship anything over 20 lbs in a cardboard box with that white "FLAKY" foam as Carl had mentioned. You get to moving a 30 pounder around in that box and it wil destroy the foam. I use the blue styrofoam and it works out good. That damn white stuff clings to everything when you try to remove it. Make a plywood box, bolt the transformer to it and add a couple of handels. I use FedEx with less mishaps than UPS or USPS.
Gary...WZ1M

[flintstone mop]

If I remember the "fan" in an '82 is a little Rotron like in a microwave oven

[KM1H]

The same centrifugal bloweris used on the 3 top of the line amps and is more than sufficient for RTTY contest duty.

A problem for many is they do not like the air flow sound so set the speed tap on low. For heavy duty you have to bite the bullet and put up with the air or remote it in another room

If you want noise get a big SS amp, you have 4 or more high speed screamers.

The AL-82 should be good for 350-400W carrier on AM as thats about the limit for the tubes and good linearity. I run a LK-500ZC at 350W carrier with the external Dahl iron PAC-5 and there are no chimneys for the tubes, just a box of 4 small muffin fans.

I agree that the transformer is not normally a problem in those big amps but the old AL-80A is notorious for smoking them.

The AL-82 is known for IED events when a tube lets loose and the damage can be severe; Ive had several in here for a rebuild.

Carl

[w1vtp]

Al, I would not even fool with Ameritron unless the amp is under warranty.  I'd instead get a higher current CCS rated transformer or get the stock one with what sounds like a high resistance short in the secondary, rewound.  
If you get bigger iron you'd have to build out the p.s. in a separate enclosure but you could put it right next to the AL-82 cabinet, get a higher volume blower and wind up with a continuous duty AM amp.


this probably has nothing to do with the tran. failure but I think the cooling in the AL-82 is through the tube chimneys only, with nothing forcing air or pulling it through the power supply.  I think the AL-82 transformer is rated at somewhere around 600 ma CCS so it is probably okay for around 300 w. AM but I'm not sure about any 20 minute geezermissions.  I keep a lot of air moving through the p.s. on my amp but I like overkill.  Mine's a Centurion with 2.8 KV and a 500 ma Dahl CCS transformer.    

"Al, I would not even fool with Ameritron unless the amp is under warranty."  The amp is under warrenty.  I do not have any options in that regard except to do what they tell me

"this probably has nothing to do with the tran. failure but I think the cooling in the AL-82 is through the tube chimneys only, with nothing forcing air or pulling it through the power supply."   Actually, air is drawn past the transformer, diode board (and equalize resistors) and then into the fan which, in turn, blows the bottom of the 3-500z socket box.  The amp runs quite cool - much cooler than my EFJ Courier.

I don't know what the current rating is but the AL-82 is speced at the following:
Power rating:
1/2 hour continuous carrier: 1500 watts (Below 18mHZ)
30 second continuous carrier: 1800 watts plus
1/2 hour PEP two-tone test: 1800 watts
30 second PEP two-tone test:1800 watts plus

I run the AL-82 at ≈250 watts and never exceed 1500 watts PEP.

I've included some photos of the AL-82 including the power transformer.  If you are familiar with an EICO 720, the transformer is right next to one. In the next two photos, you can view the place where the transformer is installed. There is a perf... opening right next the the transformer area which goes across to the opening where the fan is located. The air goes into the fan and exits into the socket box and from there by the 3-500Z's and chimneys and out through the top.  With my AM service the air is never hot, just a bit warm.  Never felt the need to check the exit temp. might be a good thing to do.

Al

PS: "If I remember the "fan" in an '82 is a little Rotron like in a microwave oven..."  Actually, Pat, I like the sound of that fan.  I'm gonna miss it.  Used to run it all night even during my TV viewing.  Kinda become a friend. 

[w1vtp]

Al: I didnt see you say if you had put an ac amp meter on the primary when you brought it up on the variac. In most cases this will tell the story. Another test would be to split the primary and see what you get for hv at about 50 volts on the primary. Now put the 50 volts on the other side primary and read the hv. Is the hv the same as the first test, if not, you have a bad primary. If its the same then the secondary miite be bad. One other thing, never NEVER NEVER ship anything over 20 lbs in a cardboard box with that white "FLAKY" foam as Carl had mentioned. You get to moving a 30 pounder around in that box and it wil destroy the foam. I use the blue styrofoam and it works out good. That damn white stuff clings to everything when you try to remove it. Make a plywood box, bolt the transformer to it and add a couple of handels. I use FedEx with less mishaps than UPS or USPS.
Gary...WZ1M

Hi Gary!  Actually, I put a 60 watt bulb in series with the primary.  That's when I observed the dull illumination followed by a flash as I brought up the Variac and at the same time heard a "ZZZZT."  So, while I didn't use an ammeter, I am confident that the bright flashing is an indication of a momentary short during the "ZZZZT."  I can do the check you recommended by splitting the primary but I'll never be able to apply full voltage due to the shorting of the transformer.  50 volts may not work but I think I can bring it up to where it is still not shorting and do your test. Right?

On the box: got any plans?  I'm a real bad woodworker.  Thanks for your interest.

Al

[K6IC]

Re the box,

Well,  a decade or so ago,  these amps were shipped in three cardboard  boxes -- the Amp cabinet,  the transformer,  and the tube/s in the third.

For my AL-1200,  each box arrived in fine shape,  including the XFMR box,  altho YMMV on that.  Good luck,  Vic

[w1vtp]

Re the box,

Well,  a decade or so ago,  these amps were shipped in three cardboard  boxes -- the Amp cabinet,  the transformer,  and the tube/s in the third.

For my AL-1200,  each box arrived in fine shape,  including the XFMR box,  altho YMMV on that.  Good luck,  Vic

Same ccmbo.  My the transformer box was trashed.  The amplifier box was so so but the inside packing was not so good.  The tube boxes, thankfully, were OK.

[W2VW]

Makes me feel slightly better about all the old junk I use.

Even new stuff can fail once in a while.

Sorry about all the trouble Al.

Your signal sure did get a lot better here with that amp.

Before long it will be history.

[flintstone mop]

OK I stand corrected on the blower for the AL82 and the rest of the Ameritron family.
I have an AL1500 and the previous owner set the fan on low speed because of the noise factor. When I got it and using AM and a 5 minute slight buzzard the box quit transmitting and sat there dumb. I figured out that it was over heating and it protected itself.
So, I moved the airflow up a notch. The noise is really not that bad. The gate setting on my processor activates in my pauses of speech and there is no on air noise.
Fred

[K5UJ]

hammy hambone hates blower noise.  look at all the appliance op on-line amp reviews that rave about brand x being quiet (often misspelled quite for some reason).  hammy does okay running slopbucket maybe but the day comes when he pushes the little AM button on his plastic radio or decides to use his PC to run RTTY.   Then the seals on the tube pins melt.  hammy probably is unfamiliar with the concept of convection cooled 833As but it doesn't matter because he can't go out and buy anything like that that's ready for the ham bands.   

To be fair, I'm not madly in love with the sound of my 180 CFM fan I put in my Centurion either, but it is added motivation to become QRV with a plate modulated rig.

Glad to hear the AL82  pulls air through the p.s.  Didn't know that.   The transformer is a tad lighter weight than I expected but I have a 2250 v. rms 1.5 A CCS potted transformer that weighs in at around 80 lbs which is (given the specs) not as heavy as I would have expected.  It probably all has to do with modern laminations. 

Al you'll probably be back in operation before Christmas but at least you have 50 w. I think it is, from the Courier.  You can do okay in the daytime with that.   

[The Slab Bacon]

Just FWIW, Everyone loves the sound of the fans spooling up on my 4X1 rig when I hit the PTT. On several occasions I have made mention of going to quieter fans and everyone in the QSO said not to, they love the sound of the fans spooling up. Between that and seeing the plate glowing bright red in the peek-a-boo window does add a nice effect.............. 

I guess it's kinda like that big KERCHUNK of a plate contactor     

[The Slab Bacon]

Al,
    (and others) I was told by a UPS driver that "Fragile" means "use for football" on UPS shipped packages. The sticker you want on your stuff is "High Value Item" This means that it is heavily insured and someone will get torn a new one if it gets destroyed because they will have to pay for it.

Just like in anything else "monry talks and BS walks"     

[KM1H]

Glad to hear the AL82  pulls air through the p.s.  Didn't know that.   The transformer is a tad lighter weight than I expected but I have a 2250 v. rms 1.5 A CCS potted transformer that weighs in at around 80 lbs which is (given the specs) not as heavy as I would have expected.  It probably all has to do with modern laminations.

As Ive said before there is a commercial CCS rating and there is a hammy hambone CCS rating. You can probably credit Dahl for making that change in reality several decades ago when the first Alpha melted down.

[W1AEX]

OK I stand corrected on the blower for the AL82 and the rest of the Ameritron family.

The early AL82/1200/1500 series (like my 2001 AL82) hard-mounted the big squirrel cage fan right to the chassis. They sound like an aircraft engine with vibrations and metallic rumbling throughout the entire amp. The later amps mount a thick/soft rubberized gasket under the fan to dampen the noise. It makes a huge difference and is worth installing if you hate the noise. For what it's worth, I made a recording of my amp before I installed the gasket and another afterwards. (Too much time on my hands?) Unfortunately, my camera batteries were low so you'll hear the stupid warning beep in both videos, but you can still tell the difference. A home-made relative sound meter is sitting on top of the amplifier to give an indication of the lower noise level following the gasket installation. I run my fan at full speed since I tend to use it a lot for continuous carrier modes.

Before -   http://www.youtube.com/watch?v=3QZULXK5YHY

After -   http://www.youtube.com/watch?v=ebYeydXveAM

Rob W1AEX

[W2PFY]

I think the secret to shipping anything is to make it light as possible while still strong,  so gravity will not become your enemy

[K6IC]

Hi Al,

Am curious about the resolution of this problem.

Do you have your amp back?  Was Ameritron good to you?  Would you make the same purchase decision if you were in the market for a new amp now?  And so on ... 

I have been thinking about an AL-82,  here,  but have been a bit reluctant,  regarding the Plate XFMR quality (even before your problem),  etc.  I have had no issues with AL-1200s here,  but the youngest one is about 12 years old.

Thanks for any info,  Vic

[w1vtp]

Hi Al,

Am curious about the resolution of this problem.

Do you have your amp back?  Was Ameritron good to you?  Would you make the same purchase decision if you were in the market for a new amp now?  And so on ... 

I have been thinking about an AL-82,  here,  but have been a bit reluctant,  regarding the Plate XFMR quality (even before your problem),  etc.  I have had no issues with AL-1200s here,  but the youngest one is about 12 years old.

Thanks for any info,  Vic

Hi Vic  I'll post responses to your questions here with quotes from your post.

Do you have your amp back?  Was Ameritron good to you?

No. They haven't even looked at it.  My queries have been met with frustrating half a$$ed responses.

Would you make the same purchase decision if you were in the market for a new amp now?

Probably not.  Hindsight? Probably would have plowed 1/5th of the money into a Class E xmtr and taken my lumps with 100 watts of PEP on SSB

My latest query with Ameritron regarding the plate transformer:

"Don't send it in at this time..."

I was going to attach the reply they gave on this post but thought better of it.  It's going to be a looonng winter

Al

[K6IC]

OK,  AL.

Thanks for the info.  Too bad that they did not treat you better,  but,  keep on them.  They owe you meaningful replies to your questions,  and the repair under warranty.

Good Luck,  keep on them.  Thanks,  K6IC

[K5UJ]

Al, misery loves company.  I was yakking away on Christmas day when the trapezoid got squishy and a gawdawful stink came out of the amp.   Pulled cover off to discover 25 W 10 ohm brown devil inrush resistor had fried in half and carbonized the pc card under it (which was what stank).   It must have never been bypassed.  Been working on it ever since having decided to use a 1.5 A 80 pound transformer to further AMize the amp and an inrush resistor mounted away on the bottom of the cabinet that I switch in and out manually.   But like you I'm running out of patience since I'd rather be spending time on getting one of the AM rigs on the air.  I just don't like having something like that leenyar sitting around broken and I'd like to have something that has some scrot while I work on a T/R circuit and the other rigs.  Seems like every winter it craps out.  Well, that 1.5 A transformer ought to run no time limit.  Maybe you can fire up your Courier?   

[KB2WIG]

 " I'll post responses to your questions here with quotes from your post. "

Sounds like its time to do one of them BLOG things. Justa posting of your daily correspondence and/or phone calls to MFjunk and their reply.

klc