[R-390] Dittmore Freimuth Filters:

[Paul Anderson]

Frank,

On Wed, Jul 1, 2009 at 1:24 PM, Frank Donnelly<goober at centurytel.net> wrote:
> Good morning All;

> I have just come into possession of a Dittmore Freimuth  R-390A
> Upon initial inspection I found the following:
> 1.  The IF deck "DAAB05-68-C-0040"  Has a set of Collins filters in it.
> S/n 34.

>     Did DF  put out an R-390A's with Collins filters?

Being early production, who knows what parts might wind up in it.
Just because most may have had DF filters doesn't mean all did.

>     I read some where that some of the early ones did have them.
>     All the wiring around the filters looks Original. Very nice
> Professional wiring and soldering.
>     So I don't think anyone swapped them out.

The military had some very, very good rebuilders.

> 2. The IF,  2nd Osc, RF decks are the same 1968 contract number.
>
> 3. The Audio and PS deck are the 1967 EAC contract. "FR-36-039-N-6-0155

Here, it still could have been "bin picking" - take what inventory is
sitting around and get it working.

>
> 4. The front name plate and the rear chassis are the same 1968 contract
> number.

I'm curious - what is the chassis serial number?  You can sometimes
get an idea from how much variation there is in those module serial
numbers.

For example, I've got a 67 EAC in my basement that is probably all
original, as the module serial numbers are all within a few dozen of
the front panel tag serial number.

> Being that It has Collins filters, my question is:
> Do I really have an actual Dittmore Freimuth receiver?

It quite possibly is.  But it depends I think mostly on the serial #
of the chassis.  If it is an early serial number, I'd say it is more
likely old inventory would have been used, including collins filters.
>
> It receives on all bands "Weakly"  I intend to restore it, but want to
> find out what I really have.
> Hope someone can tell me a little more about it.

Mostly it's all speculation, but that's half the fun!

Paul