[Elecraft] Roofing Filters, Data Modes, TXCO

[wayne burdick]

On Apr 29, 2007, at 1:00 AM, Simon Brown (HB9DRV) wrote:

> Am I right in thinking that I can run the radio in SSB (data mode), 
> engage the 6 kHz roofing filter and have about 5 kHz of flat(-ish) 
> response?

Yes.

> This being so I assume I need a 6 kHz roofing filter for the main 
> *and* the sub receiver?

Only if you want to RX with a wide filter on both receivers. In 
non-split mode, TX and RX are both on VFO A (corresponding to the main 
receiver), so just putting a 6 kHz filter on the main RX would work, 
too.

The 6 kHz filter is nice for AM as well.


>
> My office come shack is well ventilated and the temperature sort of 
> stable. Why would one buy the TXCO - what amateur operation would 
> benefit from this other than a portable expedition to Death Valley?

The stock TCXO is 5 PPM, which is totally adequate for most kinds of 
operation. If you venture into hot or cold settings you may want the 1 
PPM option.

On a related note: We're considering giving the operator a method of 
fine-compensating even the stock TCXO, making use of the temperature 
sensor on the front panel module. When we have data on this I'll post 
it. You'd have to measure the few Hz of drift at three or more ambient 
temperatures, then enter them into a menu entry. The firmware would 
then do a curve fit, if possible, and adjust its fine (1/6th Hz, 
roughly) internal reference point. But again, this is experimental.

73,
Wayne
N6KR


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