A team comprising of Dave M0IOK, Andy G0VRM, Richard G4YTV, Lyndon M0LDR and Clive G3GJA visited the Weedley site on Saturday 16th April.

The tower was lowered and a full maintenance check was done on it. The 70cm colinear antennas looked in poor shape so they were replaced and repositioned to get the best possible isolation between them. Repositioning was made possible be removal of the 13cm ATV antennas that are no longer required.

A 5GHz link head-end was installed for tests to see whether a Band C link can be established back to G3GJA's QTH for a broadband feed to the D-Star system.

Richard and Dave attacked the remains of the Hawthorn stump and sprayed the weeds.

Clive re-terminated the 70cm feeders and then ran some tests on the new 70cm antennas to measure the separation between the transmit and receive connections. There's about 33dB isolation and the filters offer a further 10dB each at 1.6MHz separation.

As the new D-Star transmitter is very clean with no noise sidebands visible down to -80dBc at 1.6MHz HF of the transmitter it was decided to put both filters in series in the receive feed to reduce the blocking of the receiver by the transmitter. This gives a total of -53dB separation which is a start but quite still quite poor.

New filters with much better performance are desparately needed unless a move to 9MHz spacing is forthcoming. It's a wonder that the old analogue repeater worked as well as it did!

Anyone with info on designs for 70cm filters or with engineering skills willing to help please get in touch with Clive G3GJA by email to :clive AT hesh.co.uk (modify to normal format.)