A normal procedure is to use the VFO and not the RIT to the exact frequency where the other station sounds fine. Because all rigs do have a bit a frequency tollerance it is normal to do that. Also you have to do that when you have a very precise OCXO or TCXO because your partner station might have no accurate frequency. Remember also that older rigs without digital VFO and analogue frequency display are a bit off frequency. Maybe 1 kHz or 2 kHz. But they are still fine today to use.
BTW the IC-7200 has a frequency stability of +/- 0.5 ppm. That is +/- 9 Hz at 18 MHz. But only frequency stability is specified but not frequency accuracy. So in practice you could end with more than 9 Hz.
Your Kenwood was fine with 50 Hz. The stability is specified with 5 ppm which is 90 Hz at 18 MHz. The optional TCXO ist 0.5 ppm.
73, Peter - HB9PJT
In a previous post, I suggested to buy a 590 Kenwood and I am retracting that suggestion. I bought one two weeks ago and had to use the RIT to make the reception on SSB sound normal. I found that the frequency was off 50 hertz and up to 100 herz at times. Might not sound like much but others had to tune off to make my signal sound OK. A new radio should not be off frequency. Bottom line is that after suggesting on my phone call that I send it back for a swap out to the dealer. Kenwood refused to authorize the swap according to the dealer. The dealer said its' test showed only 50 herz off. They said it was within specs so would do nothing due to Kenwood.So if the received signal is say 18.150.00 you would have to tune to 18.150.05 or up to hear a normal SSB voice. They would have to use rit to hear you for a normal sound as your transmit would be off 50 hertz unless you used RIT.
It cost me over 41 bucks to send it back and another hundred for a refund. My total outlay for a week with the radio was
$141. It could have been worse as normal restock was 15% of the price paid. My little Icom 7200 was on Frequency and cost over 500 dollars less, so what's with Kenwood? I had owned two previous Kenwood transceivers both dead on frequency. I am looking at an Icom 7410 for a couple hundred more base price. Kenwood suggested I buy the optional TXCO unit to put it on frequency, so if you decide on a 590 you might consider buying it and let the dealer install it.
My experience was bad, but I wish you good luck, but do not suggest to buy a 590 based on my buy experience.