Fw: Fw: Re: Fw: Re: [softrock40] Re: Bandpass filter smilter
- You would expect the third harmonic to be the predominant one with no filtering. You are using the DDS-60 for the OSC on the SR-40, right ? set to receive 1Mhz ? What are you doing to measure the harmonics ?73 Kees K5BCQ----- Forwarded Message -----From: "joe price" <joeprice@...>Date: Wed, 01 Feb 2006 23:07:08 -0000Subject: Fw: Re: Fw: Re: [softrock40] Re: Bandpass filter smilterMessage-ID: <email@example.com>
> Exactly ! I would much prefer an old tuneable WJ double
> ....but I don't have one, was going to adapt a Drake 2Bpreselector
> ...haven't done that either, and don't really want to plugand replug
> BPFs as I scoot around the HF spectrum trying otherthings.
> Looking for the "least undesirable
> 73 Kees K5BCQ
I just reconnected my test SD40 setup using DDS as 4x vfo although it
will hear the even harmonic (way down) it's the odd that is predominate.
I set DDS to 4mhz for a receive frequency of 1mhz
2mhz down 45 to 50db
3mhz down 10db
5mhz down 12db
7mhz down 15db
- --- In firstname.lastname@example.org, windy10605@... wrote:
> You would expect the third harmonic to be the predominant one with
> filtering. You are using the DDS-60 for the OSC on the SR-40,right ? set
> to receive 1Mhz ? What are you doing to measure the harmonics ?Kees,
> 73 Kees K5BCQ
I'm using a DDS30 set to 4mhz connected to base of SR40 OSC transistor
with feedback caps removed. I have a HP654 generator with calibrated
output attenuators. By using one of ROCKY'S DB lines as a reference
the test generator can be adjusted to the same line and the attenuator
read as the difference in db.
Please connect that MiniCiruit transformer and verify my results.