[R-390] Filter Options II

[Bob Camp]

Hi

I keep coming back to another option:

How many IF modules are there still out there? The world was awash in them a while back. I have a suspicion there are many more out there than one might think.
 
Bob

On Feb 17, 2013, at 5:00 PM, Perry Sandeen <sandeenpa at yahoo.com> wrote:

> List,
> 
> Wrote: With the exception of watch crystals, the whole industry of sub 1 MHz crystals is pretty much a thing of the past. Yes, there are a couple of people who will make you this or that. You better have deep pockets to get them interested in whatever you need done. Yes, one of them is a buddy, but that only goes just so far.
> 
> Yea verily.
> 
> My take of the group’s replies is that:
> 
> 1. Crystal filters are out of the question unless one does and up converter/down converter to use some of the commercial filters used in the rice box radios.  Probably a real PITA.
> 
> 2.  While ceramic filters can be used, the supply is probably extremely limited, even worse that getting a original Collins replacement filter for the “A”.
> 
> 3.  Use the Lankford roofing filter mod and stick to a 6 KHz or less bandwidth. For a $100 or so it is probably the most cost/time effective solution.
> 
> 4.  Convert your “A” to a R-725 and selling your remaining good filters on epay to help offset the conversion cost.  Takes a lot of time and patience to convert the I.F. to 6 volt filaments. (Yes Tisha, I have 3 to do when I get a-round-to-it.)
> 
> 5.  Something microprocessor based would be too complex for the vast majority of us.
> 
> Regards,
> 
> Perrier
> 
> 
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html