Not familiar with the Johnson, but the Henry was quite an interesting
amp. It had separate inputs and outputs for 6 and 2, so there was no
switching. One could also tune it for both bands so band switching was
instant. It probably could operate on both bands at once (at
significantly reduced power). There was one for sale a few years ago
and I checked it out. Henry did this by putting the tuned elements in
series, so the 2 meter parts were long leads to the 6 meter elements,
and the 6 meter elements acted as RF Choke and bypass to the 2 meter
elements. I suspect there was some interaction, but it was supposed to
operate with no retuning when switching bands. I could see how keeping
third harmonic out of the 2 meter output would be a problem. There was
also the Amplex KW-62. A pair of 4CX250s. The grid tuning tuned to
both bands, one at a time, but one had to change the head part (tunes
stayed), Even though it only took a few minutes, it was not a true
dual band amp. BTW, should anyone have a 2 meter head unit for this, I
am interested. --Mike, WV2ZOW
On Mon, Dec 25, 2017 at 8:12 PM, Herb Krumich via VHFcontesting
<vhfcontesting@contesting.com> wrote:
> A friend brought up an interesting question tonightWhy isn't any commercial
> amps made which combine 6 and 2 meters.I know many years ago there was a 6N2
> made by Henry and I believe JohnsonBut I don't think either one ran without
> problems.Is there a circuit circuit which causes a tuning problemInquiring
> minds need to knowThanksHerb K2LNS Merry Christmas Everyone
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