Topics

Product Suggestions? #80m #15m


Tom Simpson
 

Hi:

Just ordered a 40m band QCX+ and am eagerly awaiting its arrival.

 

I don't know if this is the place to make product suggestions or not, but here goes:

 

  • QCX+ Kit in 15m band
  • 50w power amp kit in 80m


Why? Because right now I am working within the constraints set by the US FCC for holders of a Technician's license, and at this point I only have CW privileges on parts of the 80m, 40m and 15m bands, so I would like to build a QCX+ and preferably the 50w power amp in each of these bands for starters. I have the 40m QCX+ kit coming and will soon order the 40m power amp kit, but the other bands are a bit lacking as far as hardware availability goes. There is a proposal afoot by ARRL to expand HF privileges for Techs and Novices rather dramatically, but who knows when this FCC will-if-ever get around to actually implementing such a thing. And yes, I am looking into upgrading to a General license, but I would still like to start with these bands and preferably at 50w.


Thanks for indulging my request.

-Tom Simpson
KM4ZOM


Shawn Reed
 

Hello, Tom.
Understood (: As far as a proposal... Crash course, and review, equal time on antennas, self test on current question sets. Be determined and confident, and you will earn a G license. And then ask yourself the question as to opening the doors wide open to the
"crowd". You would have to know Joni Mitchel, and how they, "Paved paradise, put up a parking lot". To an honest man, enjoy. sreed kf7yff.

On Wednesday, September 2, 2020, 07:33:18 AM PDT, Tom Simpson <simpsonconsulting@...> wrote:


Hi:

Just ordered a 40m band QCX+ and am eagerly awaiting its arrival.

 

I don't know if this is the place to make product suggestions or not, but here goes:

 

  • QCX+ Kit in 15m band
  • 50w power amp kit in 80m


Why? Because right now I am working within the constraints set by the US FCC for holders of a Technician's license, and at this point I only have CW privileges on parts of the 80m, 40m and 15m bands, so I would like to build a QCX+ and preferably the 50w power amp in each of these bands for starters. I have the 40m QCX+ kit coming and will soon order the 40m power amp kit, but the other bands are a bit lacking as far as hardware availability goes. There is a proposal afoot by ARRL to expand HF privileges for Techs and Novices rather dramatically, but who knows when this FCC will-if-ever get around to actually implementing such a thing. And yes, I am looking into upgrading to a General license, but I would still like to start with these bands and preferably at 50w.


Thanks for indulging my request.

-Tom Simpson
KM4ZOM


Hans Summers
 

Hi Tom

The 50W Amp can already be built for 80m. The instructions on how to do this are in the assembly manual. I have not advertised it heavily as such yet, because I have not personally made measurements for the manaul. I have one here on the bench waiting for my attention. However, several other constructors have assembled them for 80m and verified that they work fine. 

The QCX+ can be built for 15m but again, I have not personally done so and made measurements. One would expect lower Receive sensitivity and lower Transmit output power. If you want to try one for 15m then you can order a 17m one and add a note to your order form that you would like the 15m LPF, and then we will provide you with the 15m LPF components, so you can build it for 15m. Again, several people have done this and verified that it does work. But as expected, with slightly lower sensitivity and power output. 

73 Hans G0UPL
http://qrp-labs.com

On Wed, Sep 2, 2020 at 5:33 PM Tom Simpson <simpsonconsulting@...> wrote:

Hi:

Just ordered a 40m band QCX+ and am eagerly awaiting its arrival.

 

I don't know if this is the place to make product suggestions or not, but here goes:

 

  • QCX+ Kit in 15m band
  • 50w power amp kit in 80m


Why? Because right now I am working within the constraints set by the US FCC for holders of a Technician's license, and at this point I only have CW privileges on parts of the 80m, 40m and 15m bands, so I would like to build a QCX+ and preferably the 50w power amp in each of these bands for starters. I have the 40m QCX+ kit coming and will soon order the 40m power amp kit, but the other bands are a bit lacking as far as hardware availability goes. There is a proposal afoot by ARRL to expand HF privileges for Techs and Novices rather dramatically, but who knows when this FCC will-if-ever get around to actually implementing such a thing. And yes, I am looking into upgrading to a General license, but I would still like to start with these bands and preferably at 50w.


Thanks for indulging my request.

-Tom Simpson
KM4ZOM


ajparent1/KB1GMX
 

Tom,

I find 15m low in activity and it will improve but it mak be a while for sunspots to help it.

For actual activity 40 is the hot spot, 80 can be iffy based on time of day.  So I'd
suggest the order of build first 40m, then 80, and  15M.  Its more fun with high
known levels of activity.

Of course you need antennas, coax, and maybe an antenna tuner....

Allison
-------------------------------
Please reply on list so we can share.
No private email, it goes to a bit bucket due address harvesting


The Crunchbird
 

Hans,

I want a QCX+ for 160 meters. The lower frequency should work fine with the QCX+ design. 160 meters is a great band for CW and antennas are not too hard to make work there. Dave. N2SN 


Hans Summers
 

Hi Dave

No, 160m does not work with the QCX+. This is because the lowest frequency at which the Si5351A can be configured to produce a quadrature LO is 3.2MHz. 

It is possible to set up the Clk0 and Clk1 outputs to be at F and 2F (where F is the desired operating frequency) but that would require:
1) A firmware change, to operate in this mode
2) A hardware change, since the output pins of the FST3253 IC would need to be connected in a different way. 

73 Hans G0UPL
http://qrp-labs.com

On Thu, Sep 3, 2020 at 12:13 AM The Crunchbird <pulsedevil@...> wrote:
Hans,

I want a QCX+ for 160 meters. The lower frequency should work fine with the QCX+ design. 160 meters is a great band for CW and antennas are not too hard to make work there. Dave. N2SN 


The Crunchbird
 

Hans,

The frequency limitations were previously noted. I can simply cut the track and add a tiny piggyback board with an extra divider chip to cover 160M. That should be a very simple task. T1 will of course become a real dog to wind and the BPF's will be more challenging. Maybe a larger toroid could be used for T1? I may buy an 80 meter kit from you and give it a try. Meanwhile 160 meters does not suffer from the sunspot minimum as do the other bands. Indeed the bottom of the sunspot cycle and for the next two or three years after that are the best time to work DX on 160M. 

Here is a great article on 160M that will likely spur a lot of people's interest. Dave. N2SN 




Hans Summers
 

Hi Dave

But the QCX firmware doesn't include support for 160m; it would require the capability to configure the Si5351A output at 4x the actual desired operating frequency. 

73 Hans G0UPL
http://qrp-labs.com

On Thu, Sep 3, 2020 at 12:46 AM The Crunchbird <pulsedevil@...> wrote:
Hans,

The frequency limitations were previously noted. I can simply cut the track and add a tiny piggyback board with an extra divider chip to cover 160M. That should be a very simple task. T1 will of course become a real dog to wind and the BPF's will be more challenging. Maybe a larger toroid could be used for T1? I may buy an 80 meter kit from you and give it a try. Meanwhile 160 meters does not suffer from the sunspot minimum as do the other bands. Indeed the bottom of the sunspot cycle and for the next two or three years after that are the best time to work DX on 160M. 

Here is a great article on 160M that will likely spur a lot of people's interest. Dave. N2SN 




Tom Simpson
 

My kit is not even here yet and I am already loving it.  :-)

15m is a bit of an oddball and so is not all that high a priority, but the prospect of building up 40m and 80m versions each running at up to 50w (NVIS, anyone?) makes me very happy indeed.  :-)

Thanks for the feedback, Hans. This is undoubtedly going to be a whole lot of fun.

 

-Tom
KM4ZOM


Kelly Jack
 

Hans,

Is there any chance that a band option for 160M could be added to the firmware for those wishing to experiment with a lower reference crystal for the si5351? I have a QCX+ on order and am hoping to experiment with getting it running on 160m. ie lower frequency clocks with the lower reference crystal, not a 4X frequency option with divider.

73


Simon
VK3ELH


Hans Summers
 

Hello Simon

Yes, several people have requested a 160m version of QCX+. There are three ways to achieve this:

1) Use a lower frequency reference crystal. This is technically out of spec for the Si5351A but I do not believe there is any issue with doing it, on low frequencies such as 160m band, anyway. But this requires a change in reference crystal - and also the GPS frequency calibration algorithm won't work (not unless I modify it, which is headache too and there is not much code space as you know). 

2) Configure the two Clk0/1 outputs as F and 2F (where F is the desired operating frequency). This can also achieve quadrature but this requires re-wiring of the way the FST3253 MUX outputs feed the IC5 pre-amps, since the phase ordering is now different. 

3) Use a single Clk0 output at 4F and a 74AC74 divider to make quadrature. But this requires an additional chip (74AC74) and will also spoil my nice scheme of maintaining the DC bias levels during transmit, which is a big factor in avoiding/minimising audible clicks during QSK operation (full break-in). 

All these methods have various different disadvantages and I am not sure which is the best way to go. Either way, you realize you will be facing HELL for the T1 (Band pass filter and phase splitter) and to a lesser extent, L1/2/3/4... 

73 Hans G0UPL
http://qrp-labs.com

On Tue, Sep 15, 2020 at 5:52 PM Kelly Jack <kellyjack1968@...> wrote:
Hans,

Is there any chance that a band option for 160M could be added to the firmware for those wishing to experiment with a lower reference crystal for the si5351? I have a QCX+ on order and am hoping to experiment with getting it running on 160m. ie lower frequency clocks with the lower reference crystal, not a 4X frequency option with divider.

73


Simon
VK3ELH


John Baines
 

Hi all,

How about using an off the board mixer to up the 160m signals to a QCX friendly frequency.

OK it needs the same for transmit plus a 160m PA but this is all known technology and constructing it would keep us off the streets during the Covid crisis.

73
John
M0JBA

On 16 Sep 2020, at 09:27, Hans Summers <hans.summers@...> wrote:

Hello Simon

Yes, several people have requested a 160m version of QCX+. There are three ways to achieve this:

1) Use a lower frequency reference crystal. This is technically out of spec for the Si5351A but I do not believe there is any issue with doing it, on low frequencies such as 160m band, anyway. But this requires a change in reference crystal - and also the GPS frequency calibration algorithm won't work (not unless I modify it, which is headache too and there is not much code space as you know). 

2) Configure the two Clk0/1 outputs as F and 2F (where F is the desired operating frequency). This can also achieve quadrature but this requires re-wiring of the way the FST3253 MUX outputs feed the IC5 pre-amps, since the phase ordering is now different. 

3) Use a single Clk0 output at 4F and a 74AC74 divider to make quadrature. But this requires an additional chip (74AC74) and will also spoil my nice scheme of maintaining the DC bias levels during transmit, which is a big factor in avoiding/minimising audible clicks during QSK operation (full break-in). 

All these methods have various different disadvantages and I am not sure which is the best way to go. Either way, you realize you will be facing HELL for the T1 (Band pass filter and phase splitter) and to a lesser extent, L1/2/3/4... 

73 Hans G0UPL
http://qrp-labs.com

On Tue, Sep 15, 2020 at 5:52 PM Kelly Jack <kellyjack1968@...> wrote:
Hans,

Is there any chance that a band option for 160M could be added to the firmware for those wishing to experiment with a lower reference crystal for the si5351? I have a QCX+ on order and am hoping to experiment with getting it running on 160m. ie lower frequency clocks with the lower reference crystal, not a 4X frequency option with divider.

73


Simon
VK3ELH




Kelly Jack
 

Hans,

Thanks for your response.

I was definitely thinking option one.

I had thought about option 2 but presumed that the same problem with the si5351 would arise in that the F and 2F clocks would need to be synchronised / in phase in order to get a 25/25/25/25 switching cycle and we cant go below 3MHz (approx) as the ref freq again limits the lowest freq at which this can occur. Have I understood this correctly?

Option three seems less than desirable if it introduces clicks but also seems less adventurous technically.

Re toroids, I think the lpf will be straight forward in line with your lpf kit. T1 I am thinking stacking and winding like its 80 with a few more turns on the big winding. L4 thinking somewhere around 5uH will be manageable.

Didn't think of the calibration routine but I didn't think the routine ran unless specifically called via the menu and there are other ways to calibrate albeit with less accuracy than gps.

Appreciate there are limits on code space and your time though so will think of other options for 160.

73


Simon
VK3ELH


Steven Dick
 

For T1 on 160M, consider a different toroid material.  I played with a lot of toroid materials for crystal radios have been experimenting with a very low loss NiZn ferrite material: Ferroxcube type 4C65. It is not powdered iron but is very low loss/high Q  ferrite. Much lower loss than type 61 for broadcast band frequencies.  It has an initial permeability of 125. For one similar to a T50 in size,  there's one slightly bigger at 13.35mm Diameter 7.00mm Height compared to a T50 size which is 12.7mm Diameter and 4.8mm height.   Digikey carries Ferroxcube part number TX13/7.9/6.4-4C65/  This is not inexpensive at $1.04 qty 1 dropping down to $0.658 qty 50.  They may be less expensive in the international market.

https://www.digikey.com/products/en/magnetics-transformer-inductor-components/ferrite-cores/936?k=ferroxcube+4c65&k=&pkeyword=ferroxcube+4c65&sv=0&pv76=88722&sf=0&quantity=&ColumnSort=0&page=1&pageSize=25

-Steve K1RF

------ Original Message ------
From: "Hans Summers" <hans.summers@...>
Sent: 9/16/2020 4:27:57 AM
Subject: Re: [QRPLabs] Product Suggestions? #80m #15m

Hello Simon

Yes, several people have requested a 160m version of QCX+. There are three ways to achieve this:

1) Use a lower frequency reference crystal. This is technically out of spec for the Si5351A but I do not believe there is any issue with doing it, on low frequencies such as 160m band, anyway. But this requires a change in reference crystal - and also the GPS frequency calibration algorithm won't work (not unless I modify it, which is headache too and there is not much code space as you know). 

2) Configure the two Clk0/1 outputs as F and 2F (where F is the desired operating frequency). This can also achieve quadrature but this requires re-wiring of the way the FST3253 MUX outputs feed the IC5 pre-amps, since the phase ordering is now different. 

3) Use a single Clk0 output at 4F and a 74AC74 divider to make quadrature. But this requires an additional chip (74AC74) and will also spoil my nice scheme of maintaining the DC bias levels during transmit, which is a big factor in avoiding/minimising audible clicks during QSK operation (full break-in). 

All these methods have various different disadvantages and I am not sure which is the best way to go. Either way, you realize you will be facing HELL for the T1 (Band pass filter and phase splitter) and to a lesser extent, L1/2/3/4... 

73 Hans G0UPL
http://qrp-labs.com

On Tue, Sep 15, 2020 at 5:52 PM Kelly Jack <kellyjack1968@...> wrote:
Hans,

Is there any chance that a band option for 160M could be added to the firmware for those wishing to experiment with a lower reference crystal for the si5351? I have a QCX+ on order and am hoping to experiment with getting it running on 160m. ie lower frequency clocks with the lower reference crystal, not a 4X frequency option with divider.

73


Simon
VK3ELH


Virus-free. www.avast.com


Steven Dick
 

I should have also mentioned that type 61 material could also be used for a 160M T1 at low cost with adequate Q.  FT50-61 toroids are readily available. 
-Steve K1RF

------ Original Message ------
From: "Steven Dick" <sbdick@...>
Sent: 9/16/2020 7:18:27 AM
Subject: Re: [QRPLabs] Product Suggestions? #80m #15m

For T1 on 160M, consider a different toroid material.  I played with a lot of toroid materials for crystal radios have been experimenting with a very low loss NiZn ferrite material: Ferroxcube type 4C65. It is not powdered iron but is very low loss/high Q  ferrite. Much lower loss than type 61 for broadcast band frequencies.  It has an initial permeability of 125. For one similar to a T50 in size,  there's one slightly bigger at 13.35mm Diameter 7.00mm Height compared to a T50 size which is 12.7mm Diameter and 4.8mm height.   Digikey carries Ferroxcube part number TX13/7.9/6.4-4C65/  This is not inexpensive at $1.04 qty 1 dropping down to $0.658 qty 50.  They may be less expensive in the international market.

https://www.digikey.com/products/en/magnetics-transformer-inductor-components/ferrite-cores/936?k=ferroxcube+4c65&k=&pkeyword=ferroxcube+4c65&sv=0&pv76=88722&sf=0&quantity=&ColumnSort=0&page=1&pageSize=25

-Steve K1RF

------ Original Message ------
From: "Hans Summers" <hans.summers@...>
Sent: 9/16/2020 4:27:57 AM
Subject: Re: [QRPLabs] Product Suggestions? #80m #15m

Hello Simon

Yes, several people have requested a 160m version of QCX+. There are three ways to achieve this:

1) Use a lower frequency reference crystal. This is technically out of spec for the Si5351A but I do not believe there is any issue with doing it, on low frequencies such as 160m band, anyway. But this requires a change in reference crystal - and also the GPS frequency calibration algorithm won't work (not unless I modify it, which is headache too and there is not much code space as you know). 

2) Configure the two Clk0/1 outputs as F and 2F (where F is the desired operating frequency). This can also achieve quadrature but this requires re-wiring of the way the FST3253 MUX outputs feed the IC5 pre-amps, since the phase ordering is now different. 

3) Use a single Clk0 output at 4F and a 74AC74 divider to make quadrature. But this requires an additional chip (74AC74) and will also spoil my nice scheme of maintaining the DC bias levels during transmit, which is a big factor in avoiding/minimising audible clicks during QSK operation (full break-in). 

All these methods have various different disadvantages and I am not sure which is the best way to go. Either way, you realize you will be facing HELL for the T1 (Band pass filter and phase splitter) and to a lesser extent, L1/2/3/4... 

73 Hans G0UPL
http://qrp-labs.com

On Tue, Sep 15, 2020 at 5:52 PM Kelly Jack <kellyjack1968@...> wrote:
Hans,

Is there any chance that a band option for 160M could be added to the firmware for those wishing to experiment with a lower reference crystal for the si5351? I have a QCX+ on order and am hoping to experiment with getting it running on 160m. ie lower frequency clocks with the lower reference crystal, not a 4X frequency option with divider.

73


Simon
VK3ELH


Virus-free. www.avast.com


Michael N6MST
 

40 meters alone can keep you busy for years. If it were me I'd just build the 49M QCX+ and a decent antenna and play on that band until the QSX comes out. This approach does not sell as many kits (sorry Hans!) but it works with a minimum expenditure and ends up giving you access to basically everything.

And between now and the QSX release you've got time to get your Extra 😁


Christiaan PA3FUN
 

Hi Tom.
I am using the 50W Amplifier at 80m with success.
Should you need any assistance in getting it on the air just drop me a line off-list.
73s Christiaan PA3FUN