Uh Larry, the owner's manual explains how to transmit on AM mode. Won't do it very well, but it will. Uses the SSB modulator for AM. The front-panel carrier control "unbalances" the SSB "balanced" modulator, to insert a carrier for AM transmit.
By chance, are you asking how to get it to transmit on the "CB" band as well as the 28.5 band?
You'll find the the receiver on AM is a pain in the neck to use, if you are listening to more than one station on the frequency. Since the radio is still using the too-narrow SSB filter for AM receive, you'll need to "clarify" an AM station just right. Turn the tuning knob too far one way, and he'll be muffled and bassy. Too far the other way, and the receiver will slice his carrier off of his signal, and he'll sound as if HE's transmitting on SSB. Tune him in just right, and he'll sound okay. Until the next guy keys on the frequency. If the other fella's frequency is different by as much as a couple of tenths of a kHz (safe bet), you'll have to re-tune to HIS signal to clear him up. Listen to a channel with four people on it, and your hand will be glued to the tuning knob, each time someone different talks.
As if that weren't a sufficient pain in the neck, the AM transmit is using the SSB modulator. This means that you have to keep the mike gain down, to match the carrier level. You'll see a carrier power between 15 and 25 Watts if you follow the instructions for AM transmit. True PEP will be between 50 and 80 Watts, more or less. Trouble is that as soon as your audio peaks exceed 100 percent modulation, it doesn't get loud, it gets "muffled". Crank the mike gain beyond that, and you'll sound like you're transmitting on SSB. Yes, it WILL transmit AM mode, but it won't get loud. At all.
AM was an afterthought on this radio. SSB is what it was designed to do in the first place. SSB is ALL it really does WELL. So long as you don't need a noise blanker. Doesn't have one of those.
And if you're asking about making it transmit on the "CB" band like it will on "28.5", that's easy. Find the rear-most section of the band switch. It's on the rear-facing side of the VFO enclosure, next to the 6GK6 driver tube. Bridge the two green wires that are connected to the switch deck. Or, move one of the green wires over to the lug where the other one is soldered. Once that's done, the transmit relay will work on BOTH bands, rather than JUST the 28.5, as the factory delivered it.
There's a whole Yahoo group devoted to that model. Pretty sure it's called "Siltronix 1011 Bunch". Their files section has the manual, and other info posted.
It's a pretty good SSB radio, once it warms up, and gets sufficient maintenance. It's a lame AM radio, no matter how you slice it.
73