Hi Bob,

I purchased a head mag setup from 
https://www.allelectronics.com/index.php?page=seek&id%5Bm%5D=pattern&id%5Bq%5D=Magnify

And found it to be outstanding for $10.95.  This unit has a built in light that is adjustable so you don’t miss anything.  I have used it to assemble the Cricket 30, 40 and currently working on the audio filter.  I can’t believe the difference, now I need something to steady my hands !

None of my work has been SMD but this should work for you.

John

KK4ITX 

If you need a parachute and don't have one you probably won't need one again.

On Jun 29, 2019, at 18:46, wa2cky <bob.groh@...> wrote:

With a constant shift to building with SMD components (and with my 'aging' eyes), I have been looking at getting one of those USB electronic microscopes for working on SMD boards. Anyone else done any work on this topic and have any recommendations, thoughts, etc to pass on?

Bob Groh, WA2CKY

Hi, can I republish this in the QRP Quarterly with pertinent info on how my fellow hamsters can get this kit?

Mike KD5KXF

On Sat, Apr 27, 2019 at 2:03 PM WA0ITP <wa0itp@...> wrote:

NM0S has provided a very nice Hi Pass Filter Kit,
http://www.4sqrp.com/4S-HPF.php, for 4SQRP to include in it's stable of
kits. It is the same form factor as his earlier low pass filter, and
there are no toroids to wind. Spiral coils on the pcb provide the needed
inductance. IMHO this nice little filter hasn't received the attention
that it deserves.

Why a Hi Pass?
Anyone using  a direct conversion receiver probably need one to prevent
overload from local AM broadcast stations, unless that rcvr has a built
in HPF.

My QTH is abt two miles from two kilowatt BCB stations, 1240kc and 1480
kc, and they have been a problem for every direct conversion receiver
I've ever built - homebrew or commercial. Several years ago I added a
very simple HPF to a project and it helped but didnt do the job
completely.  So I added caps in series with the shunt inductors, to trap
the BCB signals and that worked fb.

While my version is ok, Dave's rendition is superior (to be expected),
and the kit's pcbs make it extremely easy to build and it looks great in
it's case.  If you have an offending BCB station or two, make them
disappear by changing C4 and C5 so as to make two series resonant
traps.  There is a nice calculator here http://www.pronine.ca/lcf.htm

Attached are schematics and performance graphs for your review, all are
screenshots from Tonnesoft's very excellent filter design program LC. 
Thanks you Jim for a fantastic program and your willingness to share a
free version.

Observe the awesome attenuation Dave's design has right off the bat. 1M
attenuation is -96db!!!  My measly effort only attenuates 1Mc 36 dB..

If you need to use a high pass filter, the NM0S/4SQRP will do the job,
and can't be beat for simplicity and effectiveness.
http://www.4sqrp.com/4S-HPF.php  I just bought one !

This Saturday musing is brought to you buy the weather, is raining and
cold here.  Questions and comments are welcome.

72 WAØITP
I love this radio stuff.
www.wa0itp.com
www.4sqrp.com

NM0S has provided a very nice Hi Pass Filter Kit,
http://www.4sqrp.com/4S-HPF.php, for 4SQRP to include in it's stable of
kits. It is the same form factor as his earlier low pass filter, and
there are no toroids to wind. Spiral coils on the pcb provide the needed
inductance. IMHO this nice little filter hasn't received the attention
that it deserves.

Why a Hi Pass?
Anyone using  a direct conversion receiver probably need one to prevent
overload from local AM broadcast stations, unless that rcvr has a built
in HPF.

My QTH is abt two miles from two kilowatt BCB stations, 1240kc and 1480
kc, and they have been a problem for every direct conversion receiver
I've ever built - homebrew or commercial. Several years ago I added a
very simple HPF to a project and it helped but didnt do the job
completely.  So I added caps in series with the shunt inductors, to trap
the BCB signals and that worked fb.

While my version is ok, Dave's rendition is superior (to be expected),
and the kit's pcbs make it extremely easy to build and it looks great in
it's case.  If you have an offending BCB station or two, make them
disappear by changing C4 and C5 so as to make two series resonant
traps.  There is a nice calculator here http://www.pronine.ca/lcf.htm

Attached are schematics and performance graphs for your review, all are
screenshots from Tonnesoft's very excellent filter design program LC. 
Thanks you Jim for a fantastic program and your willingness to share a
free version.

Observe the awesome attenuation Dave's design has right off the bat. 1M
attenuation is -96db!!!  My measly effort only attenuates 1Mc 36 dB..

If you need to use a high pass filter, the NM0S/4SQRP will do the job,
and can't be beat for simplicity and effectiveness.
http://www.4sqrp.com/4S-HPF.php  I just bought one !

This Saturday musing is brought to you buy the weather, is raining and
cold here.  Questions and comments are welcome.

72 WAØITP
I love this radio stuff.
www.wa0itp.com
www.4sqrp.com

Good net last night, checking in were:

N0XM
AC0BQ
KD0WF
W8IIE
KK5IB

Thanks and hope to cu agn next week.

-- 
72 WAØITP
I love this radio stuff.
www.wa0itp.com
www.4sqrp.com