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“What el cheapo meter/SWR meter should I get for measuring upper AM band?”
There isn’t any VSWR meter commercially available to measure a 15.219 system. However here is a unique approach and does work as I have done it.
At THIS site and about half way down the page is a schematic to a field strength meter. To use as a VSWR meter, simply insert two signal diodes at the front end of the circuit via a SPDT switch, each diode facing opposite of the other to the switch (outer pins) and the center pin (common or flip contact pin) connects to the input of that circuit.
The opposite ends of the diodes connects to a sample strip which can be made by using solid copper wire inside a small metal box. One strip end is connected to ground through a resistor, the other to one of the diodes. The other strip is connected in the same manner, but with the diode at opposite end of the sample strip. Since the circuit is an amplified detector circuit, it is not critical to have the sample strip cut at a specific length. Calibration can be done by terminating the output of the sample box with a proper non-inductive load resistor which represents your antenna load impedance, and adjust the forward direction with a variable resistor for full scale reading on the meter, and the reverse mode adjusted for minimum meter scale reading.
HERE is a PDF to a home brew VHF VSWR meter, which can be easily modified for the upper MW band frequencies. Note the sampling strip in the schematic. That is basically what you would build/use and modified for the other approach method mentioned.