[Lowfer] First Impressions: AMRAD Converter and Lowpass Filter

[Ben Hall]

On 2/4/2015 2:08 PM, Douglas D. Williams wrote:
> Hi Ben. Looks like JD and Zack got your 530 kHz situation sorted out.

Absolutely.  I wanted to play with the converter again last night but 
just did not get around to it.

> Given my correspondence with Todd, I would advise replacing that RG174
> between your LPF and converter. If you do have some spare LMR-195, that
> would be ideal, IMO.

Even better - I found some LMR-240 and appropriate connectors.  I should 
be able to install it this evening.  I'll probably replace the RG-174 
that delivers the 3 MHz from the OCXO as well.

> I happen to have a spare Todd Roberts converter. Would be interested to see
> if anyone would be interested in doing some performance measurements
> comparing the IC that Ben used with the original AMRAD IC.

I have at least one more of my custom printed circuit boards for the 
converter.  I have thought about building a second converter using the 
SOIC variant of the 74HC4053 chip so I could compare it with the 
74LVX4053 version.

That said...I'm not exactly sure what performance parameters I'd be 
looking to compare.  If folks could suggest some tests/test setups, I'll 
see if I've got access to the equipment I need to conduct them and build 
up the second unit with the 74HC4053.

thanks much and 73,
ben, kd5byb