The Johnson Messenger 11 meter transceivers used receive crystals that were 455Khz "below" the receive frequency.
For example, channel 1 is 26.965Mhz so the receive crystal would be 26.965 - .455 = 26.510Mhz. To receive 10 meter
AM on say 29Mhz, the receive crystal is 28.545Mhz (29 - 0.455 - 28.545). The transmit crystal is the actual transmit
frequency, no conversion or mixing is done in the transmit side.
A Messenger 1 transceiver can be converted/moved up to 10 meters in about an hour, once the receive and transmit
crystals are obtained.
The only change required to have a Johnson Messenger 1 transmit and receive on 10 meter 29.0Mhz AM is to replace
the receive and transmit crystals then perform the receiver front end alignment, leaving the IF stages alone followed
by aligning the transmit section. No component changes are required. To achieve full output power, place a jumper
across R52 or replace R52 with a jumper wire the retune the transmitter.
The original 10 meter Johnson Messenger transceiver was the "Viking 10 meter Messenger". E.F. Johnson said it had "10 wats
input" which is quite possible since R52, 3900 10 watt resistor was not used on 10 meters. Johnson installed R52 to lower the
input power to 5 watts when the Messengers were on 11 meters.
I have a few Johson Messengers on 10 meters
A Johnson Messenger 1
A Johnson Messenger II
A Johnson Messenger 202 single-channel Business band radio (a couple of front end components needed replacing)
A Johnson Messenger 223 using an N3ZI DDS VFO and a universal single transistor RF amp to control
both receive and transmit The crystal control synthesizer was disconnected and the VFO output was routed through a
relay to the receive mixer in receive and the driver stage in the transmitter.
I've worked both coasts, Canada, and Italy using nothing more than a
simple 10 meter inverted vee up 28 feet without an amplifier.
They all have about 5 watts output. No need for an amplifier when 10 meters is open.
73
Mike W5RKL
https://www.w5rkl.com