[Mondial]

You really need an RF signal generator to do a proper alignment. A function generator, unless its an expensive digitally synthesized one, isn't stable or accurate enough at RF freqs. A frequency counter also comes in handy to set the generator precisely on freq.

There are quite a few inexpensive service grade RF generators on ebay which may require a little work. Heathkit and Eico come to mind and these can be gotten at low prices.

Having said that, you can do a respectable alignment with what you have. In a pinch I have done IF alignments with only known freq broadcast stations and a VTVM or DVM. I believe your transmitter can be programmed to any broadcast freq and your digital receiver can serve somewhat as a frequency counter. Just keep the signal level low enough into the antenna input that you don't generate more than a few volts of negative AVC voltage. Monitor this voltage and peak the tuned circuits for max rectified AVC output at the detector. Make sure that your IF peak occurs at a LO freq of RF in + 260 kHZ and you should be fine. Then adjust Low freq padder for best signal and dial cal at 600 kHz, High freq osc trimmer at 1400 kHz for dial cal. Then peak Ant and RF trimmers for max signal at 1400 and you should be done.