[Heathkit] Heathkit sb-620/ho-13 investigated by CIA

Fri, 5 Dec 2003 12:25:32 -0500

I converted one of my SB-620 IF's from 455 to 3.3xx MHz to run with my
Kenwood R599D receiver years ago with junkbox parts and a Dip meter.
Using Tom's post of all the coil specifications would have made the job
even easier. CQ Magazine also ran an article in the 60's on a mixer
designed to allow use of the HO-13 panadapter on other frequencies.
Either way, it's not that hard to get the SB-620, or similar type scopes,
to work on other frequencies. I'm sure Heath wouldn't mind if you
"retrofit the circuit with non-Heath parts".

Pete, wa2cwa

On Fri, 05 Dec 2003 10:06:29 -0500 Jim Brannigan <[email protected]>
writes:
> I have an SB-620 set up for the Heath IF and want to use it with my 
> Collins
> 455 IF.
> 
> With the help of this list and other sources I did an extensive 
> analysis of
> the work necessary to convert the unit. I finally decided that it 
> was not
> worth the trouble, and risk, to retrofit the circuit with non-Heath 
> parts
> and an external mixer was a wiser choice.  A crystal controlled 
> SA-602 mixer
> would fit the bill and have a small parts count. An amplifier might 
> be
> needed to drive the SB-620.
> The project is scheduled for this winter and will have to be done 
> from
> scratch, I have not seen any circuits or construction articles that 
> address
> this problem.
> 
> Before anyone asks, I am not willing to swap parts.
> 
> Jim
> 
> 
> > C razy I nsane A mateur has delved into his archives and came up 
> with the
> > following posts he made sometime in the past.:
> >
> > Dan, Maybe this will help.  I think if somebody just did a little
> > experimentation with
> > available stuff and didn't get bogged down worrying about the 
> details, a
> > suitable solution could be had.  If you come up with any 
> breakthroughs,
> > please let the lists know.
> > ----------------------------
> > Post #1
> >
> > Every now and then, I see guys on the lists looking for the 
> various coils
> to
> > change the HO-13 and SB-620 to different rcvr IF's.  I have 
> uncovered an
> old
> > blueprint of those coils and I am posting the pertinent data here 
> to whom
> it
> > may concern.
> >
> > I hope this does someone somewhere out there some good.  Maybe 
> some of you
> > old Heath guys can look at this and tell us what is pertinent so 
> we can
> see
> > if there's anything out there available that is close enough to be 
> a
> > replacement without to much hassle.
> >
> > To wit:
> >
> > The 455 coil for the HO-13 is P/N 588 and has the following
> characteristics:
> >
> > Range: (uH ) 117(max) to 275 (min)
> > Preset:  123 �5% @ 790 kHz.
> > "Q": minimum @ 790 kHz.: 57 measured with 2 1/4" leads to Q-meter
> > Min. wire size: 3/41 litz
> > Wire type: S. Cel. Poly.
> > No. of turns:  Universal 133
> > % of total turns from start to tap:  23%
> > Viewed from above (screw adj. end):
> > Start: lug #3 @ 6 o'clock
> > Tap: lug #2 @ 9 o'clock
> > Finish: lug #1 @ 12 o'clock
> > Winding: Clockwise
> > Staple lugs not to protrude inside coil form
> > Form to withstand 1000 VAC terminals to core
> > Must snap into 5/16" hole in 14 ga. aluminum
> >
> > P/N 589 was this high IF coil for the HO-13:
> >
> > Range: ( uH) 12(max) to 31(min)
> > Preset:  23.6 �10% @ 2.5 MHz.
> > "Q": minimum @ 2.5 MHz.: 80, measured with 2 1/4" leads to Q-meter
> > Min. wire size: 3/41 litz
> > Wire type: S. Cel. Poly.
> > No. of turns:  Universal 43
> > % of total turns from start to tap:  20%
> > Start: lug #3 @ 6 o'clock
> > Tap: lug #2 @ 9 o'clock
> > Finish: lug #1 @ 12 o'clock
> > Winding: Clockwise
> > Staple lugs not to protrude inside coil form
> > Form to withstand 1000 VAC terminals to core
> > Must snap into 5/16" hole in 14 ga. aluminum
> >
> > On the SB-620, P/N's 775 & 776 are the same as 588 & 589 
> respectively, but
> > they have a 4th (dummy) lug at 3 o'clock.
> >
> > 73,
> > Tom
> > 
>
-------------------------------------------------------------------------
-
> --
> > Post #2
> >
> > Well it took exactly 12 minutes to get my first 2 requests for the 
> rest of
> > the dope for the SB-620 coils.  So -- here goes
> >
> > P/N 774 (must have been from earlier production):
> >
> > Range: ( uH) 2.60(max) to 5.0 (min)
> > Preset:  3.5 �10% @ 7.9 MHz.
> > "Q": minimum @ 7.9 MHz.: 85 measured with 2 1/4" leads to Q-meter
> > Min. wire size: #30
> > Wire type: SPTH S. Cel.
> > No. of turns:  19 1/2
> > % of total turns from start to tap:  37%
> > Viewed from above (screw adj. end):
> > Start: lug #3 @ 6 o'clock
> > Tap: lug #2 @ 9 o'clock
> > Finish: lug #1 @ 12 o'clock
> > Dummy: lug #4 @ 3 o'clock
> > Winding: Clockwise
> > Staple lugs not to protrude inside coil form
> > Form to withstand 1000 VAC terminals to core
> > Must snap into 5/16" hole in 14 ga. aluminum
> >
> > P/N 807:
> >
> > Range: ( uH) 3.8 (max) to 7 (min)
> > Preset:  4.8 �10% @ 7.9 MHz.
> > "Q": minimum @ 7.9 MHz.: 70 measured with 2 1/4" leads to Q-meter
> > Min. wire size: #38
> > Wire type: S. Cel. Poly.
> > No. of turns:  Universal 18 1/2
> >  Turns from start to tap:  6 1/4
> > Viewed from above (screw adj. end):
> > Start: lug #3 @ 6 o'clock
> > Tap: lug #2 @ 9 o'clock
> > Finish: lug #1 @ 12 o'clock
> > Dummy: lug #4 @ 3 o'clock
> > Winding: Clockwise
> > Staple lugs not to protrude inside coil form
> > Form to withstand 1000 VAC terminals to core
> > Must snap into 5/16" hole in 14 ga. aluminum
> >
> > and P/N 808:
> >
> > Range: ( uH) 27(max) to 56 (min)
> > Preset:  44�10% @ 2.5 MHz.
> > "Q": minimum @ 2.5 MHz 60 measured with 2 1/4" leads to Q-meter
> > Min. wire size: #38
> > Wire type: S. Cel. Poly.
> > No. of turns:  Universal 57 1/2
> >  Turns from start to tap:  16 1/4
> > Viewed from above (screw adj. end):
> > Start: lug #3 @ 6 o'clock
> > Tap: lug #2 @ 9 o'clock
> > Finish: lug #1 @ 12 o'clock
> > Dummy: lug #4 @ 3 o'clock
> > Winding: Clockwise
> > Staple lugs not to protrude inside coil form
> > Form to withstand 1000 VAC terminals to core
> > Must snap into 5/16" hole in 14 ga. aluminum
> >
> > FWIW, the coil forms vary between 1 1/4" and 1 1/2" in length.
> >
> > You guys please keep the list informed of any breakthroughs.
> >
> > Tnx,
> > Tom
> > ------------------------
> > Post #3
> >
> > A few more tid-bits:
> >
> > FWIW: the part nos. I posted should all be preceded by "40-".
> >
> > Also:  40-588 & 40-589 were vintage 1963 pieces that became 
> obsolete
> > 2/28/66, at which time 40-774, 40-775, and 40-776 were introduced. 
>  Then,
> on
> > 11/21/66 the 40-774 became obsolete, and the 40-807 & 40-808 were
> > introduced.  I have no other revisions beyond 9/15/67.
> >
> >
> > Vy 73,
> >
> > Tom

________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!