QCX 50W T1&T2


Claus, OE6CLD
 

Hi all,

I bought a QCX 50W together with a QCX 40m about 3 years ago. Build the QCX but not the amplifier (never had the time). Meanwhile I relocated 2 times and recently build a QCX Mini 30m. Now I wanted to start with the amplifier and found out that one of the toroids (T1/T2 ) has been broken I to parts.

Can someone help me please. What kind of toroids do I need to buy? Any help would be appreciated.

73
Claus, OE6CLD/DJ0DX


Timothy Fidler
 

 
Claus,
 
someone else from Europe had hte same problem and after some dimensions from him (I had some from Hans on another issue - same amp ) I came to the conclusion that two off  type T61-80s stacked would be the best approximation for the material and dimensions of T2.  
 
Type 43 is darker and glossier than type 61 material which is a dull grey colour.  Of course I have no descriptions of what you have. 
 
Long and short of it was he did that and he got 10 W out at 12 V and was very happy.  This is a non linear amp and you'd expect around 14-15 W out at 14V and quite a bit less at 12 V (his 12V might have been 12.5V for all I know).
 
The only place you can get these cores reliably in small qty is  DIz at Kits and Parts in the US. 
There is RF and Microwave in  Italia who charge a fair bit more but they have a minimum charge I believe . Have a look at the pricing and esp DELIVERY COST and TIME and work out what you are best doing. 
 
 
Don't damage those long cores (coax cores) for the main RF transformer as they are unobtainium except from Hans. Tests done for me in the UK indicate they are either 4C65 Nxp material or US (Fairrite) type -61 material - there is no practical difference between them .  NB those tests were ONLY for the COax type cores. 
 
 
Onwards and Upwards - 
if you drill very carefully or otherwise  create some pads for three standoffs in the area where the LPF is on the current  PCB there is the option to create a switched  second LPF in high rise style using Isolated pad construction on  a bit of PCB you supply .  Then you can have a dual 40 and 30 mtr "50 W " amp with frequency chosen by flicking a switch. I'd suggest you use American Zettler 12V relays from Far circuits (Fred ) in Chicago USA  if you are going to do that as these are known good to transport 40W of RF power.  Make sure you know the dimensions of them in planning any board change. I'd lie them on their sides to keep the delta board height down.
 
 
regards,


Hans Summers
 

Hello Claus

The best and easiest thing to do is to super-glue the two halves together and proceed regardless. The electrons don't care.

73 Hans G0UPL


John Pagett G4YTJ
 

All,
Notwithstanding Hans’ comment about using superglue, when I tried it in the past it set so quickly as the parts were placed together that it was impossible to get a snug fit because the set glue was too thick.

I eventually used silicone rubber, which had the advantage that with pressure the gap can be squeezed right down.

Admittedly this was with very flat faces of two transformer halves, but it worked very well on what was a commercial product.

The two parts stayed together well once the silicone had set.

John
G4YTJ


Claus, OE6CLD
 

Thanks Hans,

Will give it a try with superglue. Hope it will work.

I like the idea from Tim as well. Having 40 & 30m covered with one QCX 50W would be great.

I will try to fix the broken toroid first. If this work I will finish my QCX 50W for 30m. If everything is working fine, I will try the modification suggested by Tim. I have the complete kit including enclosure, this would be a nice small PA for CW and digital modes.

Thanks for all the tips, suggestions and help. Really appreciate it!

73,
Claus, OE6CLD, DJ0DX, EI7JZ


David Wilcox K8WPE
 

Use Superglue Gel. It sets slower. Or press the parts together and run the thin super glue into the cracks or spaces between the pieces. I have done that many times repairing my wife’s ceramic statuettes.

David J. Wilcox’s iPad

On Sep 22, 2021, at 10:18 AM, John Pagett G4YTJ via groups.io <john.pagett@...> wrote:

All,
Notwithstanding Hans’ comment about using superglue, when I tried it in the past it set so quickly as the parts were placed together that it was impossible to get a snug fit because the set glue was too thick.

I eventually used silicone rubber, which had the advantage that with pressure the gap can be squeezed right down.

Admittedly this was with very flat faces of two transformer halves, but it worked very well on what was a commercial product.

The two parts stayed together well once the silicone had set.

John
G4YTJ





M0RON
 

Use Superglue Gel. It sets slower. Or press the parts together and run the thin super glue into the cracks or spaces between the pieces. I have done that many times repairing my wife’s ceramic statuettes.

Start behaving, then she'll stop throwing them at you. 
Andy 
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.


Tony Britton <Tonymail001@...>
 

I use Bondic, not actually glue, uv setting plastic. Apply as needed, adjust position, set with uv light from the included uv led.
https://bondicuk.co.uk/


Claus, OE6CLD
 

Hi Toni,

Great idea. I still have plenty of Bondic from their Kickstarter campaign.

Will give it a try first.

73,
Claus, OE6CLD, DJ0DX, EI7JZ 


Peter GM0EUL
 

Have you successfully used Bondic on a toroid?  My experience is that it won't stick if the UV light can't get to it so it may hold the toroid just at the very edge but 99 percent of the contract area will not be polymerised and there is no strength to the repair.

You can get superglues with a few seconds delay to allow positioning.

I find Bondic is brilliant as a clamp to hold an epoxy joint.  I use epoxy to fix something, hold it tightly in position then squeeze Bondic bridges across the join and polymerise it with the UV.  The Bondic holds the joint while the epoxy cures then picks of the surface quite easily if you want a smooth finish.

73
Peter GM0EUL




Tony Britton <Tonymail001@...>
 

hello Peter, I guess you're right. I only use bondic as a temporary 'hold' before finally soldering some components. some of the QRPGuys kits are designed to use a tyrap to secure certain things. I haven't yet completed the QRPLabs kits I have so can't comment on specifict of these but  If I wanted to secure a component with significant mass particularly in a device which might be subject to shock or vibration in use then I'd look for either a mechanical support or use a final conformal coat or potting compound.


On Sat, 25 Sept 2021 at 09:27, Peter GM0EUL <gm0eul@...> wrote:
Have you successfully used Bondic on a toroid?  My experience is that it won't stick if the UV light can't get to it so it may hold the toroid just at the very edge but 99 percent of the contract area will not be polymerised and there is no strength to the repair.

You can get superglues with a few seconds delay to allow positioning.

I find Bondic is brilliant as a clamp to hold an epoxy joint.  I use epoxy to fix something, hold it tightly in position then squeeze Bondic bridges across the join and polymerise it with the UV.  The Bondic holds the joint while the epoxy cures then picks of the surface quite easily if you want a smooth finish.

73
Peter GM0EUL





--
Tony Britton
Mail; tonymail001@..., mail@...