These amplifiers were designed primarily for the distribution of 10MHz reference signals around the shack and workshop,
and other applications using signals up to about 100MHz. However, both of the devices presented here offer useful
frequency responses well beyond that original spec. As well as 10MHz reference distribution, other applications include:
routing microwave IF's to multiple receivers (eg conventional and SDR),
splitting LO outputs to drive transmit and receive converters,
sampling LO outputs to drive PLL's and Reflocks etc,
and providing the 'missing 3dB' that we so often need in our transmit chains!
distributing GPS antenna signals to multiple receivers (DA1-4G version)
In moving to a commercially produced PCB for the DA, I will only be producing the 4 way product. The functionality of the two way
DA can be obtained by simply building half of the 4 way version.
4 way Distribution AmplifierFiltering and Isolation
Note that no on-board filtering or isolation is provided in the basic kit. If you require either, then you should provide it
external to the PCB assembly. There are several web references which indicate that old ISA PC ethernet
network cards (the type with the BNC socket on the back) contain very useful 10MHz filters and isolation transformers -
there are usually two filters and up to three transformers on a single card. There is also a very useful (but not needed here!)
DC-DC voltage converter. For more detail see filters, transformers and DC converters
See also my Scatterpoint 2009 article and my
Mid Atlantic States 2009 conference paper.
Should you require filtering at other frequencies, then this is also probably best provided externally, but you may be able to implement
a simple single Pi stage on the pads provided for the attenuators, especially at the input (R3,4 and 5)
Page created: 29.07.2008
Last updated: 29.12.09