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Qcx 40m T1 winding #t1 #alignment #40m

Darren KN4WML
 

Quick question about the secondary 3 winding of the T1 toroid. It states to have 38 turns on the T1 , but I have 35? Don't know how I done that, I thought I got the correct turns on there. I seems to be working ok, but what would be the change on missing three turns???  

Ronald Taylor
 

Hi Darren. If you can get a good peak on the Bandpass Filter alignment step with the capacitor somewhere between minimum and maximum capacitance, then that turns count is probably fine. If C1 is fully meshed, though, then you will need to add a few turns to get the bandpass tuning back in range. If it’s working, then leave it alone. The old Engineer’s Motto: “If it isn’t broken, take it apart and fix it” doesn’t really apply in this case 😀.

73 … Ron

On Mon, Jun 1, 2020 at 10:52 AM Darren KN4WML <darrent78@...> wrote:
Quick question about the secondary 3 winding of the T1 toroid. It states to have 38 turns on the T1 , but I have 35? Don't know how I done that, I thought I got the correct turns on there. I seems to be working ok, but what would be the change on missing three turns???  

N3MNT
 

Did the set up values look right when you went through the process?  What is est pwr out.  If they are good, I would not touch it.

jjpurdum
 

Check your power output if you can. If you're happy with it as is, most people would rather have a root canal that redo T1.

Jack, W8TEE

On Monday, June 1, 2020, 1:52:42 PM EDT, Darren KN4WML <darrent78@...> wrote:


Quick question about the secondary 3 winding of the T1 toroid. It states to have 38 turns on the T1 , but I have 35? Don't know how I done that, I thought I got the correct turns on there. I seems to be working ok, but what would be the change on missing three turns???  

George Korper
 

T1 isn't in the output circuit, But leave it alone, if your receive is OK,
Not a good place to become obsessive-compulsive. Too many turns may 
require attention, but even three too few, the little trimmer capacitor can handle.
If the noise peak in the alignment went well, relax. 

On Mon, Jun 1, 2020 at 3:11 PM jjpurdum via groups.io <jjpurdum=yahoo.com@groups.io> wrote:
Check your power output if you can. If you're happy with it as is, most people would rather have a root canal that redo T1.

Jack, W8TEE

On Monday, June 1, 2020, 1:52:42 PM EDT, Darren KN4WML <darrent78@...> wrote:


Quick question about the secondary 3 winding of the T1 toroid. It states to have 38 turns on the T1 , but I have 35? Don't know how I done that, I thought I got the correct turns on there. I seems to be working ok, but what would be the change on missing three turns???  

ajparent1/KB1GMX
 

To those that ask about power out T1 is part of the receive side
and has NO effect on transmit power.

At most the receiver will nto be as sensitive as one mught hope.  However
if its hearing stations go with it.  Plan  is add small amounts of parallel
capacitance [across C1, C5, C8] say 10pf at a time to get T1 to peak
with C1 at about half/midpoint.

Allison
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LX2KD
 

On page 67 of the assembly instructions, it does go into quite a lot of detail about how to adjust the C1 trimmer capacitor, and how to judge whether there are too few turns on T1 secondary 3, or maybe too many.  It is quite difficult to judge because the instructions were written with a clear plastic dielectric in the trimmer, but that has been replaced by a ceramic type which makes it harder to see if the plates are completely meshed or unmeshed.  I presume that change was made because too many customers were melting the trimmer by applying too much soldering iron.  (Maybe some updated version of page 67 wouldn't come amiss.

In my case, the plates were completely mashed, so therefore I had too few turns on T3 secondary 3.  I added 5 turns as per the instructions, and it is fine now, if a bit messy.  I somehow wish I had started out with more turns than I needed and then had to reduce - it would have been neater.

But it works now, and I am delighted with the little rig.  Nice reports from USA.

Kevin, LX2KD / G4AZO

Jim Painter
 

Kevin, as per a post from Ron Taylor, C1 is max when the solder blob faces the center pin.

Jim....KQ3S


On Jun 2, 2020, at 9:37 AM, LX2KD@... wrote:

On page 67 of the assembly instructions, it does go into quite a lot of detail about how to adjust the C1 trimmer capacitor, and how to judge whether there are too few turns on T1 secondary 3, or maybe too many.  It is quite difficult to judge because the instructions were written with a clear plastic dielectric in the trimmer, but that has been replaced by a ceramic type which makes it harder to see if the plates are completely meshed or unmeshed.  I presume that change was made because too many customers were melting the trimmer by applying too much soldering iron.  (Maybe some updated version of page 67 wouldn't come amiss.

In my case, the plates were completely mashed, so therefore I had too few turns on T3 secondary 3.  I added 5 turns as per the instructions, and it is fine now, if a bit messy.  I somehow wish I had started out with more turns than I needed and then had to reduce - it would have been neater.

But it works now, and I am delighted with the little rig.  Nice reports from USA.

Kevin, LX2KD / G4AZO