Sunday, 26 January 2014

Nacton update

A little more info on progress with the Nacton transverter.
Around 35 Four metre kits have been shipped plus a number built by myself and by my Beta testers. No major problems have been identified but one or two tips to aid construction have been made.

Several 2m versions of the Nacton have been built and a number of issues identified that must be addressed before 2m kits can be shipped.

Thanks to the efforts of G4SWX the 2m filters have been redesigned for much improved performance. During the ongoing development of the transverter a few other areas requiring attention were identified and have been addressed. The PIN switches have been improved and an embarrassing problem identified and corrected...... Non saturated switching led to noise injection that raised the transverter noise floor.

John also suggested an alternative post mixer amplifier with a much higher intercept. These changes have produced a 2m transverter with an exceptionally good dynamic range.

These changes will be incorporated into a new PCB.

The good news is that several of these changes will also be incorporated into the next version of the 4m transverter.

Existing 4m Nacton transverters can be upgraded with simple cut and strap and a few component changes. Only the post mixer amplifier will require any significant change ( it uses a different package) but it can still be accommodated on the existing PCB. Since the background noise on 4m is much higher than on 2m the improved noise figure is of less consequence and the MAV11 can be retained if required. The slightly higher dynamic range that the new post mixer amplifier gives may not be too important. If it is felt to be important then it too can be changed.

I still don't know when the new Nacton kits will be available, but my hope is still in the next month or so. Due to significant delivery times for some parts and the cost of purchasing quantities, I will not have large stocks of the new kits, right away. At present I am keeping a list of requests and I'll let those on the list know when kits are available.


Sam


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Location:Falkenham Road,Ipswich,United Kingdom

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