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

[Opcom]

There is confusion in the minds of manufacturers and users alike about what CCS means.

In amplifier manuals it will say CCS 1KW, and then later on give some 50% duty cycle crap. This double-talk is not limited to cheap gear. Any mention of a duty cycle negates a statement of CCS. The true CCS power is the stated power x the duty cycle.

Excuse me for believing in technical fantasies but CCS means a 100% duty cycle limited only by regular maintenance and the occasional MTBF issue with consumables like tubes, and that any other downtime is not to be expected for decades and would be due only to severely aged components (chemical changes, etc) or damage/abuse.

CCS means "the designer expected it to operate until the end of time"

CCS operating is another concept everyone seems to avoid.

An example of CCS operating is to use the equipment only to the power level at which you would expect it to run unattended for a year (or forever).

Example is the NCL-2000. The book says 1KW input, 350W AM carrier. That will destroy it in a few weeks. CCS operation of that amp calls for about a 100-120W carrier, or about 400-500W DC input.

The old man that taught me always made CCS a clear issue.
To be plain, nothing is allowed overstress in CCS operation.

ICAS means running 4KV on 813's, and 1500V on 807's, as well as the famous 6L6 in oil. Run what you can get away with.

These are my beliefs in the religion of electronics.

It seems to be the power supplies that are the weak spots in amateur radio amplifiers and even in some of the old desktop boat anchors. The transformer is always the first place to cheapen.

Quiet fans -bah! The fan is there to move air. The reason fans in hammy gear are so noisy is because they try to use the most compact fan that will move the necessary air. Then on top of that they will skimp on the airflow to make it cheaper and quieter and let anyone who would presume to run to "single tone" or RTTY duty go hang! I have no objection to a quiet fan as long as it is physically large enough to move the right amount of air. A large-diameter slow centrifugal fan is great but hardly seen in amateur gear.

Ok I guess I have had my gripes. And I'd bet the OP has not abused his transformer but it just broke as statistics on MFJ equipment indicate it might.

[w1vtp]

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?   

Dang!

Sorry to hear the bad news. I'm missing out on the detail - is this Ameritron?  Right now I'm busy collecting parts for my Class E rig. Hoping to get that project moving  now that I have additional motivation. 

I'm trying to work an angle where I can sent a note to the management of Ameritron about this lack of capability to take care of their customers.

Good old faithful Courier was on the air the same day.  That's what I'm using right now.

Al

[WQ9E]

The market for people willing to pay for true CCS is far too small to be commercially viable in hamdom (or just about any other consumer product market).  For example, how many cars or pickups can produce their rated horsepower for any length of time without overheating multiple parts of the power train not to mention the rapid wear that occurs at peak HP RPM?  

Some of the better vintage Alpha amps could stand up to CCS but even those were a very small portion of ETO's miniscule market share.  The sales success of generally crappy Chinese goods clearly points out that consumers talk quality but cheapness (and often shortsightedness) wins out when it is time to pull out the wallet.  

I built a homebrew amp to my standards for CCS and to fit my specific needs but I could have bought a couple of Ameritrons for just my parts cost and I already had a lot of the parts (rack cabinet, chassis, filament, screen, and bias transformers, etc.)  If I compared the time I put into design and construction versus what I could have made consulting with those same hours it is an incredibly expensive amp.  But I always wanted to build a good quality amp and I enjoyed the process.

The commercial linear making firms do a good job of designing just what the SSB operating G5RV using typical Joe Ham wants to use.   But you are right, these are far from perfect for people operating AM with its combination of high average duty cycle and high peak output.  Many of these folks would be far better off using controlled carrier rigs (i.e. a Drake 4 line) since many operators don't have enough sense/understanding not to beat the hell out of their amps trying to run too much power with full carrier AM rigs.

[K5UJ]

Sorry to hear the bad news. I'm missing out on the detail - is this Ameritron?  Right now I'm busy collecting parts for my Class E rig. Hoping to get that project moving  now that I have additional motivation. 

I'm trying to work an angle where I can sent a note to the management of Ameritron about this lack of capability to take care of their customers.

Good old faithful Courier was on the air the same day.  That's what I'm using right now.

Al

Thanks Al; I see Martin Jue at Dayton and I have given him some flack in the past on for example the single 3-500 amp being sold as a 1 KW amp.   Like Patrick was saying, these manufacturers stretch things in any number of ways--they'll take the one band the amp screams on where it will put out 1300 w. let's say, and advertise it as a 1300 w. amp never mind that on a number of bands, you're doing well if you get 900 or 1 KW out. 

The one I have is a Ten Tec, the Centurion model, also a dual 3-500 amp.  It is actually not a bad product for the ham who wants a light duty table top box.  Most consumer product hams want small cabinet, quiet fan, and slopbucket duty cycle, IOW everything anathema to buzzardly continuous duty AM.  Harris used to make professional grade dual 3-500 or single 3-1000 amps--they were spec'd at 1 KW out (so the average hammy would probably sneer at them) but they were beasts--6 or more feet tall racks, broadcast transmitter style components, ... you get the idea.   Well, how many hams would plunk down $10K or more for one of those?   Most hams buy on watts per dollar.   GL on the class E rig.  I have to replace one of the relays in series with one of the 120 v. lines to the plate iron primary and I think I'll be back in business.   I made the common noob mistake of putting the cover back on (what's left of it) thinking it would work.  How foolish.   

[KM1H]

Example is the NCL-2000. The book says 1KW input, 350W AM carrier. That will destroy it in a few weeks. CCS operation of that amp calls for about a 100-120W carrier, or about 400-500W DC input.

There is nothing in that manual claiming CCS, the AM rating is 1000W Average, not senile old men lock the mike and die mode.

Ive run my HF and 6M version at a 350W carrier on and off for decades (and 1200W CW since I got it in 65 ) and never smoked anything. Finally replaced the 6M tubes a few years ago when power was down to 750W, not bad for 67 date codes. The HF one will soon be back with the 100V doing full wideband DSB AM at will.

[K5UJ]

not senile old men lock the mike and die mode.

That's the mode I want to operate 

[w1vtp]

<snip>

There is nothing in that manual claiming CCS, the AM rating is 1000W Average, not senile old men lock the mike and die mode.

<snip>

What about a 20 minute TIMTRON dissertation on modding a Valient? Or a TIMTRON 1 hour dead carrier NICAD session?

 

[KM1H]

The only time I listen to Tim is at the AM dinner where we are all on QSK mode.

Ive probably hit the 10 minute mark a few times but that blower moves a lot of air and no cabinet paint was injured during this demonstration

[Opcom]

Example is the NCL-2000. The book says 1KW input, 350W AM carrier. That will destroy it in a few weeks. CCS operation of that amp calls for about a 100-120W carrier, or about 400-500W DC input.

There is nothing in that manual claiming CCS, the AM rating is 1000W Average, not senile old men lock the mike and die mode.

Ive run my HF and 6M version at a 350W carrier on and off for decades (and 1200W CW since I got it in 65 ) and never smoked anything. Finally replaced the 6M tubes a few years ago when power was down to 750W, not bad for 67 date codes. The HF one will soon be back with the 100V doing full wideband DSB AM at will.

I never claimed the book said CCS, but it implied it by not saying much else other than 1000W input, and not giving a time limit but I could be in error.

It says "The NCL-2000 is a 1000 watt average, 2000 watt PEP linear amplifier" and "The output circuit components, power supply, and other components in the NCL-2000 are rated to allow operation at 1000 watts steady carrier input for AM, CW, FM, and RTTY service".

There is also an implied warning that the cooling fan is barely adequate: "50 cycle operation is permissible provided that the cooling fan is operated from a separate 60 cycle supply. If such a supply is unavailable, the NCL-2000 may be operated at reduced input".

During tests power transformer became too hot to touch after 3-4 hours. That is a no-no for me. They have been known to fail and I do not want to risk it so I run it at a lower power. I really like the amplifier and want it to outlast me. How to run it? - To each his own.

[WB2CAU]

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

In my teenage years I worked in a shipping-receiving department and learned how to package electronic equipment to survive rough handling.  Later in life I was doing a lot of shipping of home audio equipment for myself.  I always packaged well and labeled cartons with cautionary stickers.  Not once was there ever a damage claim on anything I shipped.

About 20 years ago when routinely bringing a carton to the UPS customer counter for shipment, I was scolded by the counter clerk for marking the carton with "fragile" labels.  He said to NEVER use those labels.  I asked him why and he replied that it only incites the handlers to purposefully mishandle the carton.  I was shocked and asked why doesn't UPS fire workers who treat parcels in that manner?  He shrugged his shoulders and said, "It's a changing world". 

I think a recent posting on YouTube showing a callous a FedEx employee throwing (and ultimately destroying) a delicate parcel over a fence (rather than carry it through the gate to the door), brought this mishandling of parcels by shippers to the public's eye. 

The lesson?  Package it as if the carton will be mishandled in the worst possible manner and make sure that the contents are never disclosed (on the outside of the carton) to the handlers. 

Eric

[KM1H]

Interesting comments however Ive run the NCL-2000 in a 24 hour CW and SSB contest many times and it never got any hotter than my Alpha 76CA or comparable amp in similar service. Ceramic tubes run hot which disturbs some but the maximum seal temperatures are not even close to being exceeded as long as the full cooling system is in good repair.

I never claimed the book said CCS, but it implied it by not saying much else other than 1000W input, and not giving a time limit but I could be in error.
It says "The NCL-2000 is a 1000 watt average, 2000 watt PEP linear amplifier" and "The output circuit components, power supply, and other components in the NCL-2000 are rated to allow operation at 1000 watts steady carrier input for AM, CW, FM, and RTTY service".

Thats all it says and implies nothing else; its an ICAS duty amp and not marketed to CCS requirements. National had a seperate product for that.

The blower was also changed after the first production run due to the large and unexpected orders from the 50Hz world; but both my HF and 6M 2000's are prototypes with the original versions and still running fine. Of course I do clean and lube them which includes the impeller plus tube fins.

Excessive transformer heat can usually be traced to leaky or improper high ESR electrolytics. And these days also likely is excessive AC line voltage since it is spec'd at 115/230V. There are also many different transformer temperature ratings based upon acceptable temperature rise which is tied into the wire insulation and winding insulation used.

That amp was installed in many US embassies and also used extensively by the Norwegian government, all on 50Hz of course. The only reported problems were poor efficiency on some frequencies that were far away from ham bands so I designed a different tank circuit and frequencies covered that was a drop in replacement as well as a standard option for new orders.