WA1ZMS Transatlantic VHF Beacon gets Upgrade
The WA1ZMS Trans-Atlantic beacon/transmitter project has had a recent upgrade to its operation.
Technical Description: QTH: FM07fm at 4200ft AMSL Antenna: 2 6ele yagi stack aimed at 60 degrees to Europe ERP: 7kw!
From Brian Justin, WA1ZMS/4…
A land mobile grade base station VHF exciter is used and the 25w driver PA is keyed for CW modulation. The exciter utilizes a 10MHz frequency reference with is derived from an HP-Z3801A GPS frequency standard. The TX frequency is 144.285MHz and is stable to within 1E-10Hz, although propagation effects will likely cause much more observed frequency error than the GPS standard can provide.
A new higher power PA has been added as well as an upgrade to the physical rack cabinet and requisite power supply, etc.
RF power out of the transmitter is now 500w and is driving a new pair of Sinclair 6-element yagis. After LPF, circulator, bandpass cavity filter, and feed line losses the ERP is now at the 7kw level. This is likely the highest power 2m beacon currently on the air.
The new PA is a home brew design using a pair of MRF151G push-pull devices operating with PCB Wilkinson splitters and coax delay lines to allow for true quadrature operation of the pair of 300w amplifier pallets.
All QSL reports are welcome and can be sent to:;[email protected], although
trans-Atlantic QSL reports will be given the highest priority!
So those of you interested in the;Brendan Award;keep an ear out. This service will go a long way towards helping us out. n