I am in the middle of evaluating the RX-320 for review. The evaluation sample was about 100cycles off frequency making frequency readout using ECSS or SSB slightly inconvenient.

I devised a procedure to put the receiver exactly on frequency. Read through it and if you are comfortable and have the tools, give it a try.

1- Set the receiver to WWV on a frequency appropriate to strong, clear reception and allow the RX-320 to warm up for at least an hour. With the receiver on either LSB or USB, verify that there is no beat note and also, that the voices which announce the time sound natural. They should be at or very close to the same pitch when the receiver is set to SSB as when it is set to AM. If it is not, follow steps 2, 3, 4, 5 and 6:

2- Remove the 4 side screws (2 on each side) and carefully remove the top cover.

3- Orient the receiver so it it topside up, front facing you. (The Ten-Tec emblem will be facing you and on the upper left). Mounted on the PC board approximately nearly all the way forward and just to the left of what would be center line is a crystal (shiny metal case about 1/2" tall) all by itself with a brown trimmer about 1/8" in front if it. That brown trimmer sets the master oscillator frequency.

4- Using a small jewlers or a ceramic screwdriver, gently adjust the brown pot in the direction that causes any beat note to go lower in pitch until it is gone. The gentlest touch and further finer adjustment will make the voices announcing the time sound completely natural.

5- When this is complete, the receiver master oscillator is zero beat and if you were very careful, the frequency readout will be accurate to the actual received frequency within a few cycles.

6- Reassemble the RX-320.

Message: 2 Subject: Re: RX 320 zero beat procedure

I strongly recommend only using WWV at 15 MHz to do this offset fix. The RX320's offset error, while essentially linear, is a function of frequency. Most receivers, most of the time, require more negative offset at lower frequencies than higher ones. It's also a function of temperature and can vary 10 Hz betwwen a cold room and a warm one. 15 Mhz, being right in the middle of the RX320's range, would be ideal if you were only going to compensate at 1 frequency.

Don't try to adjust on the voices. Wait for the pulsed tone instead of the clicks and then switch from LSB to USB until it's a dead on match.