SB-303 NB

[w1id]

On Tuesday, March 27, 2001 at 10:27:11 AM, Jim Roik wrote:

> I did that with an SB303 myself way back when. It was cut into the IF stage
> and a switch was mounted somewhere to turn it on and off. If my memory
> serves me correct, there should be two short pieces of coax going to the
> noise blanker board. To reverse the mod all you have to do is remove the
> board and connect the coax straight through. To set up the blanker all you
> had to do was adjust the overall gain control on the blanker board.
>
> What I can't remember is if the mod came from QST or where.
>
> It was a very valuable addition to the SB303, one that I would not remove.
> If I ever get an SB303 again, it is a mod that I would want to put into it,
> So if you decide to pull the noise blanker board and get rid of it, I would
> like to stand in line to get it.
>
> Jim  VE4AQ
>
> > -----Original Message-----
> > From: Heathkit Owners and Collectors List
> > [mailto:HEATH at LISTSERV.TEMPE.GOV]On Behalf Of Gary Harmon
> > Sent: Tuesday, March 27, 2001 8:24 AM
> > To: HEATH at LISTSERV.TEMPE.GOV
> > Subject: SB-303 NB
> >
> >
> > Thanks for the replies and suggestions on the SB-303 Noise Blanker.  It is
> > in fact a SB-104A NB mounted inside the chassis.  Does anyone have the
> > article or specification sheet for this modification?
> >
> > Thanks in advance.
> >
> > 73,
> >
> > =====================
> > Gary H. Harmon, Jr.
> > K5JWK
> > 6302 Robin Forest
> > San Antonio, TX  78239-3218
> > (210) 657-1549
> > gharmon at idworld.net
> > =====================
> >
> > Listserver Subscription:listserv at listserv.tempe.gov - "subscribe
> > heath 'name' 'call'"
> > Listserver Submissions: heath at listserv.tempe.gov
> > Listserver Unsubscribe: listserv at listserv.tempe.gov - -"signoff heath"
>
> Listserver Subscription:listserv at listserv.tempe.gov - "subscribe heath 'name' 'call'"
> Listserver Submissions: heath at listserv.tempe.gov
> Listserver Unsubscribe: listserv at listserv.tempe.gov - -"signoff heath"
>
>
The noise blanker mod was in fact published in QST. I don't have the issue dates at the moment (I'm at work) but I can get the info later on if anyone is interested. This same blanker was also added to a Collins receiver. I have added the "104" blanker to my SB-303 and really could not bring myself to remove it as I live in a noisy urban environment and a noise blanker is a must. I wish I lived in a quiet area but such is life. I'm only 2 minutes away from the Interstate and access to many good jobs. It works best when the band is not too crowded as the blanker is susceptible to strong signal overload. But then you don't need a blanker under strong signal conditions anyway. In my installation, I used the upper left front panel countersunk screw hole to mount a miniature pot. Then I used an extra aluminum fiducial adjustment knob for the pot so that the mod looks more like an original. As for the MFJ filter I think I would have either left it in its own enclosure or at most put!
 it inside the SB-600 cabinet. It sure would be a lot easier to restore an SB-600 front panel than have an SB-303 front panel with extra holes.

w1id
e-mail: w1id at fcgnetworks.net

Listserver Subscription:listserv at listserv.tempe.gov - "subscribe heath 'name' 'call'"
Listserver Submissions: heath at listserv.tempe.gov
Listserver Unsubscribe: listserv at listserv.tempe.gov - -"signoff heath"