General Rule: Never trust tune-up of a tube amplifier to anyone under 50 years of age. On 5/7/2022 3:04 PM, Mark K3MSB wrote: > Greetings. > > The gang up the radio club managed to blow the amp several weeks ago while > tuning up. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus