The reason I recommended 4-811s over the 3-500 is because I think that tube availability makes the choice a bit more future proof at this point...


Of course, a good deal on a used 3-500Z amp with good tube could easily affect that decision as I like the tube, too.  But you ain't gonna find a good EIMAC anymore.  



KE3WD

Tokyo Hypower makes the HL-350VDX , 330W 2 meter amp powered by 120/240VAC, HRO sells 'em for around $900US.


But a used tube amp would be the thing to find IMO in order to save $$$.  

Be sure to google the tube in question if you find an amp first, make sure of availability and price of new tube these days.


KE3WD

BTW -- Shortened first dit in QSK will likely not be a problem at all with the speeds listed here.  

Somewhere up past the 30WPM mark would be when the shortened dit can start proving problematic.  


!

>>by HA6SST on September 11, 2007  

"Thank you for all the replies. A formula of 1200/wpm is easy to remember, all I need to do now is cure my problem of a shortened first dot when the transceiver changes over."<<

You might want to take a look at QST magazine tests, both for your rig and others, before you drive yourself crazy here.  

That first dit length is indeed problematic for many, if not most rigs.  

QST typically publishes an oscilloscope graph of the first dit element length for every rig tested.  

Almost all of them are shortened to some extent.  

Another test where TenTec and Elecraft transceivers often come out doing better, just another reason that they are loved by serious CW ops I guess.


--KE3WD

Google the "A-E-R-N-T" method of learning the letters.  


AERNT, starts with the shortes and simplest characters and builds in five letter groups rather than attempting to memorize the alphabet in alphabetical order.  

That method is time proven and is the fastest.  

There is an older free piece of software called, "Morse Academy" that will use this time-honored and US military method of learning the letters, like having classroom instruction actually, using the computer as your virtual one-on-one instructior.  

Still one of the best methods I've ever found for learning the code, also teaches typing copy on the qwery keyboard at the same time, a plus if you ask me.  

http://www.speroni.com/AH0A.html

Note the instructions and "other" piece of software necessary for running this grand old piece of code under XP.  


Once you learn all the characters using Morse Academy, you can then let it send you random versions of the old CW "QSO" tests for practice like on-air, like playing a computer game.  You can also load any text file into MA and have it play back as CW, a great way to practice "head copy" when you get to that point, push your speed, etc.  


In all this time, I've found none better, really.  


--KE3WD

This is a good thing.  

I hope experienced CW ops get out there and do the right thing with it.  

Might be a good time for the old hands to treat this like Straight Key Night experience, too, break out the old stuff, which would be far less boring for us older CW ops than simply jacking the old Lionel J-38 into the modern rig, eh?  

Just make sure ahead of time that the old rig comes down off the shelf for a shakedown, let's not have a buncha "sick chickens" out there for the noobs to try to copy, okay?  (grin)

The old Heathkit PS malady, y'know.

"Bawk-Bi-Baw-Bick, Bawk-Baw-Bi-Baawwwk"

HI


--KE3WD

I agree with the concept that if you feel you have to ask this question, best to go with the current value leader, the AL-80B.  

You can't beat that for the money and you will get a warranty, etc.  

Of course, keeping your eyes peeled for a good deal on a used AL-80B can *sometimes* save money, but be advised that there are many out there who sell an amp only when and if they have abused it to the point that it has become problematic.  If you can vet the owner, such as someone you know from a local ham club, or perhaps have good reason to know that the used amp comes from a good home, consider the used deal.  

Leave the older amps, the SBs, the 30L-1s, etc. for us hard core solder-breathing hams with the larger  inventory of experience and junk box parts when looking for your first amp, there will be enough to learn with the pristine AL-80B.  Maybe later on you might pick up an older amp for a new learning experience, after you are familiar with what to expect, how to tune, etc.  


KE3WD

Like 2mS differential is consequential...

If you take a minute to examine the Ameritron schematics, you will find that simple potentiometer voltage divider circuit I'm talking about.  

Long before Ameritron used this method I was successfully employing same in my own amp/rig interface homebrews.  

When I first came up with the idea, my only concern was whether or not the ALC voltage might not be linear in operation.  That was easy enough to confirm with my own two amps I had at the time, but wasn't sure if all amps used the same implementation.  That was over 12 years ago, haven't run into an amp yet that wasn't.  

One pot will do this if your amp doesn't have an ALC adjustment at the back and the specs say that the ALC output is a higher voltage than your rig is designed to use.  

Copying the circuit from any Ameritron manual schematic is the way to go if you don't understand my written description.  

I prefer to put the pot in an external enclosure along with my keying buffer circuitry rather than modify an amp that doesn't have the pot on it.

This is a simple project -- and well worth it IMHO.  


KE3WD

>>Why the jumper to complcate things???<<

Very likely because there is another accessory meant to plug into that connection that requires defeat of the circuit in the rig.  Transverter, maybe.  Or maybe they designed for something that never made it to market, too.  


KE3WD

A DMM or VTVM across the ALC line can determine if the ALC output is higher than the prerequisite 4V in very short time.  

Many amplifier designs incorporate a pot adjustment at the back for ALC output adjustement, typically just wired as an adjustable voltage divider, if your ALC is nonadjustable and the output measures higher than the rig's max ALC input spec, very easy to put a potentiometer wired as voltage divider inline.  Adjust it once and done.  


KE3WD

Send them another short note, sometimes mail gets misplaced, lost, etc.  

Um, a schematic would be more apropos here...

Silicon junctions, the rectifiers in this case, can often be faster than fuses.  They make great fuse protectors...

I say you should replace the tubes, or at the very least that one tube, very soon.  

Waiting for it to fault and possibly make an internal short *could* be expensive, much more expensive than what the price of the replacement tube would be at this point.  

Continued operation is a risk I would not take.  


KE3WD