[HBQRP] VFO Toroid saga

Fri Nov 25 11:19:35 EST 2005

I'll have to admit that after having used both, I prefer the wooden one
also. Like you said, you can apply power with the board in the holder plus
it seems more stable to me. I also added some features such as rubber
banding a "film can solder dispenser" to one of the support legs along with
putting a small nail in one of the feet to hold a toroid in place when
tinning the leads. Also a small nail on the side to hold a spool of solder
wick.

Wife and daughter went to Walmart at sunup for sales this morning. The $399
laptop computers (15 each) were gone in the first 10 minutes the clerk said.
Sniff, sniff !

Hope everyone is "recuperating" today.

Now to work on the T-1 tuner ............Steve/WBØQQT

----- Original Message -----
From: "K0AWB at Cox.net" <k0awb at cox.net>
To: "Midwest Homebrewers Group" <hbqrp at mailman.qth.net>
Sent: Thursday, November 24, 2005 9:33 PM
Subject: RE: [HBQRP] VFO Toroid saga

> Steve...
>
> I found one thing I like about your original wooden PC board holders...  I
> can power the circuit while it is the holder without having to worry about
> shorting anything. :)
>
> I hope everyone had a HAPPY THANKSGIVING...
>
> I'm trying to work off the turkey with a soldering iron... I don't think
> it's gonna work... having too much trouble bending over the workbench to
see
> what I'm doing :)
>
> Darrel... K0AWB
>
> -----Original Message-----
> From: hbqrp-bounces at mailman.qth.net
> [mailto:hbqrp-bounces at mailman.qth.net]On Behalf Of Darrel Swenson
> Sent: Wednesday, November 23, 2005 5:54 PM
> To: Midwest Homebrewers Group
> Subject: RE: [HBQRP] VFO Toroid saga
>
>
> Steve...
>
> I got a chance to play with some toroids this afternoon...
>
> I wound 29 turns of 22 gauge, 26 gauge, and 30 gauge on 3 T50-6 cores.  I
> also tested the original with 29 turns of 24 gauge.
>
> 29 turns, 22 gauge, T50-6 = 2.435 MHz
> 29 turns, 24 gauge, T50-6 = 2.456 MHz
> 29 turns, 26 gauge, T50-6 = 2.475 MHz (2.40 - 2.48 MHz)
> 29 turns, 30 gauge, T50-6 = 2.350 MHz (2.28 - 2.41 MHz)
>
> 28 turns is really about all the 22 gauge wire that will fit on a T50
core.
> I got 29 on, but a couple of the windings don't lay completely flat.  The
24
> and 26 gauge fit fine.
>
> The 30 gauge is pretty loose.  I was able to play with it a little... by
> pressing the winding closer together the oscillator frequency went down.
> Spreading them out equally caused the frequency to go up.  I could move
the
> frequency from 2.28 to 2.41 by compressing and expanding the windings.
>
> I got the same results with the 26 gauge wire, but not as much swing.
>
> The 24 and 22 gauge wire are too tight to move much.
>
> I'm guessing this is why designers use the largest wire gauge that will
fit
> on the core... better stability.
>
> I couldn't find any reference to 2.4 MHz VFO frequency either.  It does
say
> the IF is 7.68 MHz...
>
> So... 10.1 MHz operating frequency - 7.68 MHz IF leaves 2.42 MHz for the
> VFO.
>
> We still have to add C7 and the tuning diode so the final frequency range
> will changed slightly.
>
> Darrel...
>
> -----Original Message-----
> From: hbqrp-bounces at mailman.qth.net
> [mailto:hbqrp-bounces at mailman.qth.net]On Behalf Of ssellmeyer
> Sent: Wednesday, November 23, 2005 4:41 PM
> To: K0AWB at Cox.net; Midwest Homebrewers Group
> Subject: Re: [HBQRP] VFO Toroid saga
>
>
> Ohhhhhhhhhh Noooooooooo ! !  I just rewound it for 40 M  with the present
23
> turns............and I have a 30M kit. Duhhhhhhhhhhhhh. I forgot the Elmer
> 101 is for a 40M version. Duuuuuuuuhhhhhh #2
>
> I looked thru the instructions that came with the kit but didn't see where
> the 2.4 Mhz was referenced anywhere.
> Oh well. Back to the drawing board !
>
> SteveWBØQQT      P.S. Yes Dar, we are Grrrrrrrrrrr..........having fun
> now.........I think !
>
>
> ----- Original Message -----
> From: "K0AWB at Cox.net" <k0awb at cox.net>
> To: "ssellmeyer" <ssellmeyer at inebraska.com>; "Midwest Homebrewers Group"
> <hbqrp at mailman.qth.net>
> Sent: Wednesday, November 23, 2005 2:50 PM
> Subject: RE: [HBQRP] VFO Toroid saga
>
>
> > Steve and everyone...
> >
> > Sounds like you are having fun experimenting.  Keep winding those
toroids.
> >
> > As I was winding toroids this afternoon... I was trying to figure out
why
> > Steve was getting such different results than I did... then it occurred
to
> > me...  he isn't... :)
> >
> > The VFO in the 40 meter version runs at 3.000 - 3.035 MHz with a 4.00
MHz
> IF
> > to cover  7.000 -  7.035 MHz (40 meters)
> >
> > The VFO in the 30 meter version runs at 2.420 - 2.455 MHz with a 7.68
MHz
> IF
> > to cover 10.100 - 10.135 MHz (30 meters)
> >
> > The VFO in the 20 meter version runs at 5.000 - 5.035 MHz with a 9.00
MHz
> IF
> > to cover 14.000 - 14.035 MHz (20 meters)
> >
> > I thought the 25 turns on L1 sounded familiar... that's the number I
just
> > wound on L1 for the 40 meter version I'm building.
> >
> > The 40 meter version uses 25 turns for a 3.0 MHz VFO.
> >
> > The 30 meter version has 4 more turns to drop the VFO frequency down to
> > 2.4..something MHz.
> > So if 23 turns = 3.071 MHz.
> >       25 turns = 2.890 MHz
> >       27 turns = 2.625 MHz
> >       29 turns should be about 2.4 MHz... for 30 meters.
> >
> > Don't worry about getting the VFO exactly on frequency, we calibrate it
in
> a
> > later step.
> >
> > 73... Darrel... K0AWB
> >
> > -----Original Message-----
> > From: hbqrp-bounces at mailman.qth.net
> > [mailto:hbqrp-bounces at mailman.qth.net]On Behalf Of ssellmeyer
> > Sent: Wednesday, November 23, 2005 12:03 PM
> > To: Midwest Homebrewers Group
> > Subject: [HBQRP] VFO Toroid saga
> >
> >
> > Short and sweet, here are this mornings experiments. As stated earlier I
> had
> > 27 turns of # 22 wire on the toroid which gave me 2.625 Mhz.
> >
> > After removing 2 turns (now at 25 turns) I had 2.89 Mhz. Looks like I'm
> > getting there eh ??
> >
> > Removing two more turns (now at 23turns) I have 3.071 Mhz. Think I'm
going
> > to leave it there and see what happens later.......if anything.
> >
> > I was Talking to KØNG, Charlie, last night here in Lincoln on 2 meters
and
> > told him the situation. He is an RF design engineer for Telex here in
> > Lincoln and has bailed me out on occasions too numerous to mention here.
> He
> > explained it to me as the same as trimming a dipole for the resonant
> > frequency you are trying to achieve. In other words you remove turns to
> > raise the frequency or add turns to increase. Made sense to me !  It
> appears
> > to have worked. How about that. This old dog learned something ! !
> >
> > Dale, in regards to the Radio Shack freq. counter and using a probe, I
> tried
> > your method of NOT physically touching the board at Q2. I played around
> with
> > resistor leads, a sewing needle and insulated wire but could not get a
> > reading unless I touched it physically. I used the sewing needle to
touch
> it
> > with since my RF probe also uses a needle. I agree with you on the
> > possibilites of loading, interaction etc. Many thanks for the tip. I'm
> here
> > to learn and you guys are a big help.
> >
> > Lunchtime.............Steve/WBØQQT
> > ______________________________________________________________
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> >
> >
>
>
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