[TenTec] Roofing Filters

Bill Tippett btippett at alum.mit.edu
Thu Aug 5 11:27:05 EDT 2004


W4CAK:
 >Thanks for your input with all the backup info regarding the 500 HZ 
roofing filter.  I will just use the 1KHZ filter from now on when trying to 
copy weak signals. I went to Inrad's website and did not see the 762 filter 
listed for sale yet.

         It IS for sale now but you may have to send them an E-mail.
I suspect the price is around the same as their other filters.
Last I heard deliveries should begin late Summer but I could be
wrong.

 >When you pull the 1KHZ filter out and replace it with the Inrad 600HZ 
filter, are you replacing the 1.8KHZ filter with the 1KHZ filter like some are?

         My thinking has changed on this recently.  I seldom operate
SSB but like the 1800 Hz for SSB contests.  My original configuration
was to move the 1000 Hz to the 1800 position, and simply swap the
1800 in for my annual CQ WW SSB Contest.  However, I have now set
aside my 1000 Hz (I park it in the 500 position with that position
disabled), and leave the 1800 enabled.  My reasoning is:

1.  Measurements by Sherwood have shown that the 1800 is equivalent
to the 1000 for IMD at moderate spacings (down to 2-5 khz).

2.  If you really need close-in IMD performance (<2 kHz), you want
the 600 Hz anyway and not either the 1000 or 1800.

3.  The 1800 is there in case you need it for SSB contests or perhaps
SSB DX-ing without having to manually swap any filters.  In an SSB
contest, I never use anything but the 1800 so manually locking it in
place is simply part of my pre-contest set-up.

         To summarize regarding configuration with the #352 600 Hz:

A.  If you are a CW-only op, you have no need for the 1800 Hz, so move
your 1000 to the 1800 slot (which is empty).

B.  If you operate both modes AND have the 1800 Hz filter (which is
probably only really necessary for heavy-duty SSB contesting), set
your 1000 Hz aside when you put the 600 into the 1000 slot.

                                                         73,  Bill  W4ZV





More information about the TenTec mailing list