NCL-2000 Date codes

[KE5PUT]

I just acquired an NCL-2000 and I would like to know when it was manufactured.

There are two numbers on the amplifier; one is on the back panel, 71-3739, and the other is on the top of the chassis inside the case, 71-3058.

I would make a guess that 1971 is the year of manufacture and the last four digits are assembly sequences or number of units made.

Does anyone know how to determine the age of this amplifier?

73's

Jerry-KE5PUT

[KM1H]

No cigar, the 71 is the first production run from 63-65

The number on top of the chassis is sequential and was added after the chassis was stamped. The back panel has the actual serial number and is also sequential of how they went into the shipping box.
Its a bit retarded compared to the way they did it for decades prior where only one number was used and it really meant a single run done at one time and not something that sputtered along as needed to fill orders.

I dont know how long the 80 run took to finish, I was gone by then

Carl

[Opcom]

Congratulations on owning a really nice amp. I love mine.

Watch the screen current like a hawk. Under-loading the amp can do damage and 8122's are costly.

[KE5PUT]

Thank you for the date code info.

I am working my way through the amp checking resistor values, ESR's on the electrolytics, and continuity through switches and tube sockets.

So far, all seems to be in great shape. This unit is optioned for 80 watt or less exciter source. That suits me too.

Hope to bring up power next week.

Jerry-KE5PUT

[KM1H]

There is no good ESR test for HV electrolytics other than a suitable PS and a meter. Any original caps or any more than 20 years old should automatically be replaced.

The transformer screen winding is so marginal it will fail if you look at it the wrong way.

See the discussion on here a few weeks ago about a screen current regulator for that amp.

I havent used my signature on here in a long time so here goes

Carl
KM1H
National Radio 1963-69
Service Tech, Service Manager
Member of NCL-2000 and NCX-1000 Design Teams
Amplifier and Boatanchor Service
HRO-500 a speciality

[Opcom]

Read this thoroughly! I have not done anything to mine but this work is very informative.
http://ncl-2000.n9efj.net/ncl2knewman.html

[KM1H]

Yeah 1500W....sure!!

And I see he didnt include the author of those Service Bulletins either....ME

Plus he missed a lot.

I didnt look at it in details to comment on the rest....yet.

Carl

[N9EFJ]

I'm sorry.

Sometime ago you asked me to remove any reference to you on my site.

I did.


I enjoy using my amp and thanks for your
participation in it's design.

Carl

BTW Are there any bandswitch assemblies available?

[KM1H]

Sometime ago you asked me to remove any reference to you on my site.

I dont remember the reason, probably I disagreed with the other content which I still do as mentioned above. It is not a 1500W amp for example.
I'll read it all when I have time.

BTW Are there any bandswitch assemblies available?

I sold over 150 NOS full BS/coil assemblies on fleabay and kept enough for my and customer needs as the NCL's come in regularly. Got 2 in this month and one had a blown switch.
Next step will be to have new wafers made.

Carl

[W2VW]

If the bland switch sells that well there's a problem which won't be fixed by another bland switch.

[Opcom]

I have not looked at mine in a while. Is it a ceramic switch?

as for power.. size of transformer and cooling tells me 1KW average input - that is what the old book says, right? "a kilowatt in every sense of the word" - I think it's right. I also know that thing gets very hot running a KW input for a long time so I do not.

In my opinion it is short on anode airflow but maybe I like things cool. At one point I built up a "wind chest" for it to sit on that used a much larger blower to push much more air though the amp. That was when I was using it to make RF for experiments. Everything stayed cool, the power transformer and the tubes.

I'm not aware of a blower improvement.

[KM1H]

Yep, its a ceramic switch of similar size to the SB-220, SB-1000, AL-80 family, and others. After almost 40-50 years of use the regular cycling plus RF heating takes its toll.

It wasnt made to last forever.