Eighteen members and guests were present for the dissemination of equipment belonging to former member Dennis, M0JXM who passed away on the 12th of August, 2021.  Total donations came to £108.50 which will be sent to the British Heart Foundation as requested by the family.

Regular meetings will restart on the 13th of January, 2022.

Have a Very Merry Christmas and a Safe and Prosperous New Year!

Don began by telling the short history of the VNA. He then described the make up of the unit and the various iterations through it’s history. Don warned the early ‘Gecko’ version had been the subject of many fakes.

Although the VNA can work as a ‘stand alone’ it is easier to use connected to a lap top running readily available software. The initial calibration was straight forward since the step by step instructions are provided at each step of the action.

He began a live demonstration by measuring the VSWR and Impedance of an eight element yagi for the high end of 70 cms followed by a 2 m yagi. Both aerials were hand held and the VNA displayed the slight changes in the VSWR as they were moved about. Also strung up in the hall was a 20 m dipole which was shown to be in tune. Measurements of the passband of a high pass filter Don had built showed it was working as designed. He also measured TDR to find the length of various pieces of coax cable. Measurements made can be stored and recalled later. Don explained several of his files.

He pointed out that the single port device can not only measure VSWR but impedance, phase, return loss, TDR,  and produce Smith charts. The dual port device can also measure filter response and loss as well as check cavities and traps for response.

Unfortunately the VNA is supplied without a case, but an inexpensive ABS shell is available from other suppliers.