While cleaning out other Ten Tec items to sell, I found this: Ten Tec Model 206A outboard crystal calibrator, settings for 25 KHz and 100 KHz. Black case matches Argonaut 515. From nonsmoking shack. $30, shipped Priority Mail in US. Personal check or postal money order OK. Don’t do Paypal. 73, Winston K4CWQ Sent from my iPhone