Elecraft Amplifier to be announced at Visalia CA Hamfest

Manual tuning takes me only a few seconds. Really.
High voltages are dangerous only if not managed properly.
It's no big deal to wrap glass jugs separately, just like when you move.

AF6LJ = Sue.

I figure it is easier to build an "ATU" at the same time as a PA, and in one box.

 

That was me that posted that.
And as far as I can see that wouldn't be a good reason to move to LA.

 

Henry never included 160m in any of their amps until the 3K Premier.

In the old days, there was a good reason as we weren't allowed kW-level power on 160 then, anyway.

In more modern times when we were, they had this real "thing" about not using toroids in high powered amplifiers and wanted to avoid them at all costs; big air-wound inductors for 160m would barely fit.

Someone finally convinced them to add 160m to the 3K, in 1986. That was "me." Ted Henry said he'd only do it if I gave him an order for at least one dozen amplifiers, paid in advance. That was done, in July 1986, and the Henry 3K Classic MK III using a 3CX1200D7 and including 160m was the result. I kept one and sold the other eleven to members of YCCC and FRC who all agreed they'd take them. Writing that check for about $36,000 was exciting.

The Classic MK III quickly became the "3K Premier," and from that point forward they included 160m. And used a huge air wound inductor, no toroids, to do it. It actually worked very well, with broad, stable tuning and 1500W output with ~65W drive.

 

The problem with SS is that there are far, far more "cheap hams" out there who are willing to live with high voltage, manual tuning, and fragile glass in return for saving thousands of dollars.

It's no accident that Ameritrons sell so well despite their somewhat checkered QA record. The demand is concentrated on the low, affordable end.

For the same reason, I'm glad to see Elecraft come out with the KX2, which is likely to easily outsell the KX3.

73,
Cathy
N5wVR

 

I think it goes without saying that the high cost of solid state amplifiers is the result of the protection circuits needed to keep them from melting down under less than ideal conditions and higher than desired drive.
If you dump all the protection circuits the cost on a watts per dollar basis is very close to each other.

 

^I agree; but there's also the cost of all the bandswitched filtering required, which gets pretty hefty at those power levels.

Tube amps don't have any "filters," just the tuned output network, which may have only 3 to 6 components plus a switch.

And SS amps usually have more "cooling" elements than tube amps. You can cool a 1500W tube amp with one fan or blower at relatively low rpm so they can be pretty quiet. SS amps generally have only enough heat sinking to survive with more powerful cooling systems which you can often hear; they could reduce those a lot by using beefier heatsinks, but aluminum extrusions, copper heat spreaders etc. all cost a lot of money and might make the amp "bigger," which is a downside.

Amps that include 12/10 meters also have frequency counters built in to detect the drive frequency and lock out 26-28 MHz in order to pass FCC certification which is required for HF amplifiers.

I don't think anyone is making a fortune selling ham amplifiers.

 

I would agree for the most part, but I would add.
A low voltage high current switching supply is cheaper to build than a high voltage supply, some of that added cost of all those filters and relays seen in an SS amplifier would be offset by the reduced cost of the power supply.
As far as cooling goes.
Tubes can operate at 200 degrees C and up to 250 degrees C for ceramic metal external anode tubes.
The transistors even modern ones have a Life vs Temp curve (although this has changed a great deal in modern times with cleaner more precise manufacturing methods) 150C is the limit most of these devices can handle under normal operation.
I wouldn't run anything solid state that hard.

 

Neither would I.

Tubes like heat. They can't work without it.

I think HV power supplies are very inexpensive to build except for the transformer(s)! Everything else is cheap. I remember when Henry was making a lot of amplifiers in the 70s-80s they used a local transformer company here in the L.A. area and practically owned it because they were such a big customer. They probably got a really good deal.

 

You can buy a telecom grade switcher that will deliver 48V at 50 amps for the cost of building a 3000V 1.0A power supply. So the power supply cost might be neutral in this discussion.

As for preferred operating temperature for SS devices, I prefer to keep them under 60C.

 

$6000 sounds like a lot of dough for an amp...until you look at all the things you don't need with such a unit.

One amp for 160 thru 6.....no tune and bulletproof......real QSK....no spare tubes....small and lightweight.....Elecraft factory support......and more.

I hope Elecraft succeeds with it.