Date   

Re: Suggestion for the NEW UBITX V7.

Ashhar Farhan
 

Gordon,
The laptop power supplies give 65 watts each, even if we do use two of them together (apart from being unwieldy), we would be able to draw 120 watts of power, that would give us about 60 watts output (at 50% efficiency). 
I started playing with IRFZ24N transistors yesterday, I blew up 4 of them! Good stuff. Let me report back  again in a few days.
- f

On Tue, Oct 20, 2020 at 8:38 AM Gordon Gibby <docvacuumtubes@...> wrote:
Laptop 65Watt 19VDC supplies are relatively cheap.   They do have some significant RFI problems in my experience.  Thankfully, if not doing QSK CW, you may be able to de-power them with some clever circuitry during Receive (when their RFI is a problem).  

Two of these supplies in series would give 38VDC @ 130W and presumably provide enough power for a 50W output system.   I'm not an RF designer, but could you use two parallel semiconductors and power one from two supplies, and the other from two other supplies and add the output together somehow to get 100W output?   

Perhaps there is a solution to the cost of the DC power supply.   
THanks,
Gordon KX4Z


On Mon, Oct 19, 2020 at 11:02 PM Sila <kasovoni@...> wrote:
Hello Tom,
Noticed this statement from the seller:
Even with EMI/RFI filter built inside, still not suitable for a hamradio operator connecting with radio or wireless communication equipment. 

Have you noticed any problems with the power supplies?

-Sila. 


Re: Solid-state T/R switching #ubitx

MadRadioModder
 

I’ve been using BAP64’s for RF switching… they are super cheap… about 27 cents and only take about 7-8 volts to switch.  They are good to about 24 dbm or so (250 mW).  But you can even use 1N4004’s for RF switching at moderate power…

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Ted via groups.io
Sent: Sunday, October 18, 2020 7:23 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Solid-state T/R switching #ubitx

 

Thanks, Bill.

No, I'm not trying to eliminate relays from the board, only the function of the T/R so that I can get the recovery for "semi" QSK a little faster.... and it is semi-QSK if I don't have to manually move a lever or a knob from TX to RX in between words.  If I can get that between letters, that would sure be nice as a sunny day.  

I'd like to volunteer that, in no way am I implying commentary upon the original design; I'm just carrying on with the intent of the kit by experimenting and modifying to suit.  

I've had one of the original T/R relays in a V3 die on me, and an Axiom T/R relay die on me in a V5, in far fewer than the tens of thousands of cycles these are typically rated for.  So, of course, accepting in advance that CW is not the primary role of these radios, I'm looking at making my portable box (and likely a Bitx-40 board I came across as well) into something that is more suited for the quick-recovering and wear-free picture of a true CW rig.   The reason for posting is that of wondering if I'm on the right track with something like FET's switching on in opposition to each other per TX/RX duty, rather than the usual PIN diode route, due to this design sharing so much of it's core for both TX and RX paths.  

Tnx, 

Ted 
K3RTA

 


Virus-free. www.avg.com

--

…_. _._


Re: Suggestion for the NEW UBITX V7.

Gordon Gibby
 

Laptop 65Watt 19VDC supplies are relatively cheap.   They do have some significant RFI problems in my experience.  Thankfully, if not doing QSK CW, you may be able to de-power them with some clever circuitry during Receive (when their RFI is a problem).  

Two of these supplies in series would give 38VDC @ 130W and presumably provide enough power for a 50W output system.   I'm not an RF designer, but could you use two parallel semiconductors and power one from two supplies, and the other from two other supplies and add the output together somehow to get 100W output?   

Perhaps there is a solution to the cost of the DC power supply.   
THanks,
Gordon KX4Z


On Mon, Oct 19, 2020 at 11:02 PM Sila <kasovoni@...> wrote:
Hello Tom,
Noticed this statement from the seller:
Even with EMI/RFI filter built inside, still not suitable for a hamradio operator connecting with radio or wireless communication equipment. 

Have you noticed any problems with the power supplies?

-Sila. 


Re: Suggestion for the NEW UBITX V7.

Sila
 

Hello Tom,
Noticed this statement from the seller:
Even with EMI/RFI filter built inside, still not suitable for a hamradio operator connecting with radio or wireless communication equipment. 

Have you noticed any problems with the power supplies?

-Sila. 


Re: memory manager/alignment

Gordon Gibby
 

This is the kind of system that I used to calibrate my V3 so long ago.   Once you measure the exact frequency, which was typically about 3 kHz off, you just put that frequency into the software and re-compile.   Bingo!   

It’s been a long while since I did it, but that’s such an easy way to do things.  


On Oct 19, 2020, at 14:23, AndyH <awhecker@...> wrote:

Mitchel,

   I found the crystal measurement routine I use - it's a very short sketch from ND6T from Feb, 2017.  As we only need the actual crystal frequency for this part of the cal, this does exactly what we want.  it sets the Raduino to output a 25 MHz signal on the clock 2 line.  Let it run 20 or 30 minutes until temperatures stabilize, then measure the clock 2 output with a counter.  That number goes into the firmware for the actual 25 MHz crystal frequency.

   OM Cantrell's code follows - it's 20 lines.  Source:  http://www.nd6t.com/bitx/Calibration.htm

/*
 Calibration program for Raduino
 Don Cantrell,ND6T  v 1.1          8, Feb 2017
 Compiles under Si535 library v 2.0.1
 This source file is under General Public License version 3.
 Generates the reference clock frequency so that it can be 
 measured and substituted as the corrected frequency of the
 particular oscillator. 
 */
#include <si5351.h>
Si5351 si5351;
 
void setup() {
    
    si5351.init(SI5351_CRYSTAL_LOAD_8PF,25e6L,0); 
    si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
    si5351.set_freq(25e8 , SI5351_CLK2); 
}
void loop() {
}

    73, Andy

On Fri, Oct 16, 2020 at 11:38 AM, Mitchel Rought wrote:
is it possible to change the display frequency through memory manager, after alignment this radio is slightly off, web sdr 7.050.000, this radio 7.049.700, I realize it's not much but still bothers me


Re: memory manager/alignment

AndyH
 

Mitchel,

   I found the crystal measurement routine I use - it's a very short sketch from ND6T from Feb, 2017.  As we only need the actual crystal frequency for this part of the cal, this does exactly what we want.  it sets the Raduino to output a 25 MHz signal on the clock 2 line.  Let it run 20 or 30 minutes until temperatures stabilize, then measure the clock 2 output with a counter.  That number goes into the firmware for the actual 25 MHz crystal frequency.

   OM Cantrell's code follows - it's 20 lines.  Source:  http://www.nd6t.com/bitx/Calibration.htm

/*
 Calibration program for Raduino
 Don Cantrell,ND6T  v 1.1          8, Feb 2017
 Compiles under Si535 library v 2.0.1
 This source file is under General Public License version 3.
 Generates the reference clock frequency so that it can be 
 measured and substituted as the corrected frequency of the
 particular oscillator. 
 */
#include <si5351.h>
Si5351 si5351;
 
void setup() {
    
    si5351.init(SI5351_CRYSTAL_LOAD_8PF,25e6L,0); 
    si5351.set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
    si5351.set_freq(25e8 , SI5351_CLK2); 
}
void loop() {
}

    73, Andy


On Fri, Oct 16, 2020 at 11:38 AM, Mitchel Rought wrote:
is it possible to change the display frequency through memory manager, after alignment this radio is slightly off, web sdr 7.050.000, this radio 7.049.700, I realize it's not much but still bothers me


Re: Suggestion for the NEW UBITX V7.

Tom, wb6b
 

On Mon, Oct 19, 2020 at 02:26 AM, Ashhar Farhan wrote:
As I said, the hidden cost really is the power supply. A 200 watts power supply is expensive.
Here is a 24v supply similar to the 12V supply I use with my vintage Kenwood. The only issue I have with the 12V version is I need to turn it and the radio on 15 minutes before the net. As it has a noise spur that drifts right onto the net frequency and lingers there for a minute or so. After that it is off somewhere else and it doesn't bother my checking into the net.

The supply I have does have filter chokes on the AC input. Looks well constructed. Don't know how they can make these for these prices. Maybe putting the supply in a metal box with some bypass caps would eliminate the spur issue. 

https://smile.amazon.com/dp/B07QPCTB3D

The 24V supply (240W) linked is $22, I think the 12V one I use (300W) cost $19.

I would think 40 or 50 wats would be more then enough output power to produce a solid signal at a reasonable cost.

Tom, wb6b


Re: Rx while transmitting #ubitx

Rubens Kamimura
 

Oi Marchetti,

GOOD IDEA, I WILL TEST.
 73/51 PY2PVB



Em seg., 19 de out. de 2020 às 13:53, edoardo marchetti <mentorade@...> escreveu:

Hi Rubens,
Try to change the antenna, I tried today and I notice a huge reduction in the feedback! The effect lasts until now but it is enormously reduced. So it could be really the rfi. You would better use a dummy load.
73
IU6DBK

On Mon, 19 Oct 2020, 15:16 Rubens Kamimura, <rubens.kamimura@...> wrote:
Evan

Photos

--
Saudações fraternais, 73/51 PY2PVB

Rubens Kamimura
Tel. (18) 3746-8680 ramal 116
Cel. (18) 9-9819-2225 WhatsApp ou (18) 9-9819-2255 


Em seg., 19 de out. de 2020 às 09:59, Evan Hand <elhandjr@...> escreveu:
Rubens,
I would check the audio wiring.  When you changed boxes, did you add an audio amplifier?  If so, see if you can shield the wiring or use a snap-on ferrite to reduce the RF getting into the audio amp.  I suspect that is your issue.

More details including pictures heps us with diagnosing your issue.  By details, I mean any changes in modules or added circuit boards.  Also the new box information; was it a kit like one from AmateurRadioKits?

73
Evan
AC9tu


Re: Rx while transmitting #ubitx

Evan Hand
 

On Mon, Oct 19, 2020 at 08:10 AM, Rubens Kamimura wrote:
Photos
Rubens,
I do not know what the board is above the low pass filters.  What is it and is that in the correct position?  If it has to do with the audio then it could be the feedback point.  My guess is that is the audio amp for the case speaker.  If that is so, then having it so close to the output could be an issue.  Can you move it more towards the front of the rig, and maybe use coax on the antenna lead?

73
Evan
AC9TU


Re: Rx while transmitting #ubitx

edoardo marchetti
 

Hi Rubens,
Try to change the antenna, I tried today and I notice a huge reduction in the feedback! The effect lasts until now but it is enormously reduced. So it could be really the rfi. You would better use a dummy load.
73
IU6DBK

On Mon, 19 Oct 2020, 15:16 Rubens Kamimura, <rubens.kamimura@...> wrote:
Evan

Photos

--
Saudações fraternais, 73/51 PY2PVB

Rubens Kamimura
Tel. (18) 3746-8680 ramal 116
Cel. (18) 9-9819-2225 WhatsApp ou (18) 9-9819-2255 


Em seg., 19 de out. de 2020 às 09:59, Evan Hand <elhandjr@...> escreveu:
Rubens,
I would check the audio wiring.  When you changed boxes, did you add an audio amplifier?  If so, see if you can shield the wiring or use a snap-on ferrite to reduce the RF getting into the audio amp.  I suspect that is your issue.

More details including pictures heps us with diagnosing your issue.  By details, I mean any changes in modules or added circuit boards.  Also the new box information; was it a kit like one from AmateurRadioKits?

73
Evan
AC9tu


Re: Suggestion for the NEW UBITX V7.

MadRadioModder
 

On that subject it would be better to pick the output devices to match existing surplus markets for power supplies.  For example, there are a plethora of very cheap commercial 48VDC supplies on the surplus market that came from the cell market.  The last batch of supplies I bought (48V 15A) cost me $120 for ten of them (plus shipping)… they all worked.

 

MRM

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Ashhar Farhan
Sent: Monday, October 19, 2020 4:26 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Suggestion for the NEW UBITX V7.

 

More than market, is that what we would personally want? As I said, the hidden cost really is the power supply. A 200 watts power supply is expensive. A pair of IRF530s can easily give us 100 watts or nearabouts.

- f

 

On Mon, Oct 19, 2020 at 2:47 PM iz oos <and2oosiz2@...> wrote:

Yes, 100w is what the market wants. Because... It drives well the OM2500...

 

Il lun 19 ott 2020 10:26 AM Murray Wills (ZL2IQ) <murray@...> ha scritto:

It sure would sell well.

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Gordon Gibby via groups.io
Sent: Monday, 19 October 2020 9:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Suggestion for the NEW UBITX V7.

 

The market likes 100 W output.  

 

In large amplifiers, the price is typically two dollars per watt output. 

 

If someone could come up with a 100 W output amplifier, separate cabinet, connects easily to a QRP rig for $200, I think it would sell pretty well

 

50 W at $100 would also sell pretty well.  

 

My 2 cents worth

 

Gordon

 

 

 

 

On Oct 19, 2020, at 02:00, Ashhar Farhan <farhanbox@...> wrote:



 I wonder how many want higher output. The same IRF510 pair with 25v on the drains can easily push out 40 watts. They will need beefier heatsinks.

The real is the power supply. At present a 7812 regulator can run the ubitx.

At 50 watts output, we are looking at 12v/10A or a 24v/5A supply. Will it be worth the investment to go for that? Power supply is the challenge.

I have looked at PC SMPSs. The ATX supply can provide this juice. However, it is noisy. The noise sidebands extend quite a bit. The other option is a laptop power unit, it supplies 65 watts at 19v, it can power upto 30 watts of RF output.

The real beast would be using the MRF101AN, it costs 20 dollars and puts out very low distortion 100 watts. It needs a 50v supply with 2.5Amps. 

Sigh, can anyone here design an Arduino based smps for us all? Seriously.

 

On Mon 19 Oct, 2020, 6:25 AM KD2QMZ, <syracusepro@...> wrote:

Any plans for a higher output transceiver with filtering etc, 160-6 for example?

 

 

On Sun, Oct 18, 2020, 3:32 PM Ashhar Farhan <farhanbox@...> wrote:

I remember my first look at a factory built transceiver (otherwise, all the hams in my town had a rack full of valve equipment that often pushed out 40 watts of CW from an 807)...

Saad Ali, President of FARSI (india's equivalent of ARRL) was visiting town and he was carrying an Atlas. We strung up a dipole at a hotel's roof and he walked in with just a small bag. The grossly misnamed 'Atlas' turned out to be a box slightly smaller than a shoebox. he switched it on and just kept working station after station. No PA Load/Tuning, no preselector, no valves. Just tune and talk! 
I had to inkling of however in the world I would be able to afford anything like that. My most prized possessions were two JFETs, a 12v transistor radio power supply and a rusty iron. Looking back at the ubitx sitting on my desk, I still think I am almost there. TheAtlas-210x had 100 watts output, it had AGC, it had a punchy receiver from an all analog circuitry and a free running VFO that was bandswitched!

- f

 

On Sun, Oct 18, 2020 at 11:15 PM Vic WA4THR via groups.io <vhklein=ptd.net@groups.io> wrote:

Following the discussion about having equipment affordable by a new young ham starting the hobby, I looked back at what I paid when I first got on the air in 1964:

 

  $59.95 Knight-Kit R-55A Receiver (6 months before getting licensed, might have been a Christmas Present)

 $10.95 Knight-Kit crystal calibrator option for the R-55A, so I could get within 1kHz of a correct frequency!

 $49.95 Knight-Kit T-60 Transmitter (ordered the day my license arrived, 60w input and 20-30w output)

$120.85 Total cost spent as I already had a microphone, headphones, wire for an antenna from being a SWL

 

Equivalent today: $1,014.67 or about the price range of an IC-7300 station and needed extras

 

But, look at the current uBitX V6 for $200 that comes with all but a power supply and antenna for $200, that would have been only $24 in 1964! These wonderful radios knock down a lot of barriers to entry for the hobby! Oh what I would have given to have one of these back then...

=Vic=


Virus-free. www.avg.com

--

…_. _._


Re: Enclosures

vu3gwn
 

This has been my attempt with VU3SUA's kit. I believe they are working on a case of V6, the existing cases can be used to upgrade. 



Re: Rx while transmitting #ubitx

Rubens Kamimura
 

Evan

Photos

--
Saudações fraternais, 73/51 PY2PVB

Rubens Kamimura
Tel. (18) 3746-8680 ramal 116
Cel. (18) 9-9819-2225 WhatsApp ou (18) 9-9819-2255 


Em seg., 19 de out. de 2020 às 09:59, Evan Hand <elhandjr@...> escreveu:

Rubens,
I would check the audio wiring.  When you changed boxes, did you add an audio amplifier?  If so, see if you can shield the wiring or use a snap-on ferrite to reduce the RF getting into the audio amp.  I suspect that is your issue.

More details including pictures heps us with diagnosing your issue.  By details, I mean any changes in modules or added circuit boards.  Also the new box information; was it a kit like one from AmateurRadioKits?

73
Evan
AC9tu


Re: Rx while transmitting #ubitx

Evan Hand
 

Rubens,
I would check the audio wiring.  When you changed boxes, did you add an audio amplifier?  If so, see if you can shield the wiring or use a snap-on ferrite to reduce the RF getting into the audio amp.  I suspect that is your issue.

More details including pictures heps us with diagnosing your issue.  By details, I mean any changes in modules or added circuit boards.  Also the new box information; was it a kit like one from AmateurRadioKits?

73
Evan
AC9tu


Re: Ubitx V3 - No tx issue #v3

Praba Karan
 

My issue was broken legs of gate and drain of left MOSFET. After bridging broken legs, issue resolved.


On Sun 18 Oct, 2020, 10:21 PM rajesh huddar, <pumerah@...> wrote:
Prabha check Q90. If this is gone like in my case, then your job is done.

On Wed, 7 Oct 2020, 20:04 Praba Karan, <vu3dxr@...> wrote:
I have noted no transmission from my ubitx V3.
But Rx is working nicely.
I noted following observations during my troubleshoot.
1.during Rx - current draw 300ma
2. During PTT - current draw 500 ma
3. during PTT with loud halllow - current draw 600ma.
4. Adjusting bottom pot ( RV2 or RV3) have no effect on current consumption to PA (contrary to upper pot.)
5. During adjusting PA bias, no heating noted in left IRF510 even at full clockwise position of bottom pot. ( Contrary to right IRF510).

Can I assume that one of final irf510 went QRT? 


Re: Rx while transmitting #ubitx

Rubens Kamimura
 

Hi
I would like help from you, I changed the box of my uBITX v4, now I am listening on the speaker while transmitting FT8, this did not happen before. Would anyone have any information?
73's de Rubens py2pvb.


Em dom., 18 de out. de 2020 às 17:50, edoardo marchetti <mentorade@...> escreveu:

Hello everybody,
This is the first time I check the transmission mode. Power output is ok, no emission in ssb without modulation but if I speak to the mike I ear my voice on the headphones. 
What could be the problem? I ear relay switching and also changing lcd writings
Thanks for reading
IU6DBK


Re: Suggestion for the NEW UBITX V7.

Bob Lunsford
 

Here is an amp offered on eBay that provides 100W with 10W drive. Here's the catch...

— It has to see no more than 2.5:1 SWR — This means an ant tuner is probably necessary unless the antenna is under this SWR
— It has to have a low pass filter (LPF for 20M and up is built in, this means a LPF for 80M and 40M is needed)
— For digital/CW, it should have a fan like from a computer but perhaps smaller in physical size.

I've seen several versions of this same amplifier as little as $37... This one is $76.60

Radioddity has this in a nice box for about $199 designed for Xiego radios but easily modified for other QRP rigs. Link is below.




On Monday, October 19, 2020, 4:11:33 AM EDT, Gordon Gibby <docvacuumtubes@...> wrote:


The market likes 100 W output.  

In large amplifiers, the price is typically two dollars per watt output. 

If someone could come up with a 100 W output amplifier, separate cabinet, connects easily to a QRP rig for $200, I think it would sell pretty well

50 W at $100 would also sell pretty well.  

My 2 cents worth

Gordon




On Oct 19, 2020, at 02:00, Ashhar Farhan <farhanbox@...> wrote:


 I wonder how many want higher output. The same IRF510 pair with 25v on the drains can easily push out 40 watts. They will need beefier heatsinks.
The real is the power supply. At present a 7812 regulator can run the ubitx.
At 50 watts output, we are looking at 12v/10A or a 24v/5A supply. Will it be worth the investment to go for that? Power supply is the challenge.
I have looked at PC SMPSs. The ATX supply can provide this juice. However, it is noisy. The noise sidebands extend quite a bit. The other option is a laptop power unit, it supplies 65 watts at 19v, it can power upto 30 watts of RF output.
The real beast would be using the MRF101AN, it costs 20 dollars and puts out very low distortion 100 watts. It needs a 50v supply with 2.5Amps. 
Sigh, can anyone here design an Arduino based smps for us all? Seriously.

On Mon 19 Oct, 2020, 6:25 AM KD2QMZ, <syracusepro@...> wrote:
Any plans for a higher output transceiver with filtering etc, 160-6 for example?


On Sun, Oct 18, 2020, 3:32 PM Ashhar Farhan <farhanbox@...> wrote:
I remember my first look at a factory built transceiver (otherwise, all the hams in my town had a rack full of valve equipment that often pushed out 40 watts of CW from an 807)...
Saad Ali, President of FARSI (india's equivalent of ARRL) was visiting town and he was carrying an Atlas. We strung up a dipole at a hotel's roof and he walked in with just a small bag. The grossly misnamed 'Atlas' turned out to be a box slightly smaller than a shoebox. he switched it on and just kept working station after station. No PA Load/Tuning, no preselector, no valves. Just tune and talk! 
I had to inkling of however in the world I would be able to afford anything like that. My most prized possessions were two JFETs, a 12v transistor radio power supply and a rusty iron. Looking back at the ubitx sitting on my desk, I still think I am almost there. TheAtlas-210x had 100 watts output, it had AGC, it had a punchy receiver from an all analog circuitry and a free running VFO that was bandswitched!
- f

On Sun, Oct 18, 2020 at 11:15 PM Vic WA4THR via groups.io <vhklein=ptd.net@groups.io> wrote:

Following the discussion about having equipment affordable by a new young ham starting the hobby, I looked back at what I paid when I first got on the air in 1964:

 

  $59.95 Knight-Kit R-55A Receiver (6 months before getting licensed, might have been a Christmas Present)

 $10.95 Knight-Kit crystal calibrator option for the R-55A, so I could get within 1kHz of a correct frequency!

 $49.95 Knight-Kit T-60 Transmitter (ordered the day my license arrived, 60w input and 20-30w output)

$120.85 Total cost spent as I already had a microphone, headphones, wire for an antenna from being a SWL

 

Equivalent today: $1,014.67 or about the price range of an IC-7300 station and needed extras

 

But, look at the current uBitX V6 for $200 that comes with all but a power supply and antenna for $200, that would have been only $24 in 1964! These wonderful radios knock down a lot of barriers to entry for the hobby! Oh what I would have given to have one of these back then...

=Vic=


Re: Suggestion for the NEW UBITX V7.

iz oos
 

I detest high power. CB amplifiers by RM-Italy likes the RP203 use 4 IRF in push-pull. They work in SSB mode. I heard they would work in class B. They are really cheap, nelle 50 euro. They miss LP filters and deliver easily more than 100w. I think the market misses a 100-200w PA in class AB or similar with LP filters at an affordable price. So, I don't think 10w are too low. I would be glad to see in the market a simple Linear PA kit 100-200w that could be swapped among qrp radiosa.


Il lun 19 ott 2020 11:26 AM Ashhar Farhan <farhanbox@...> ha scritto:
More than market, is that what we would personally want? As I said, the hidden cost really is the power supply. A 200 watts power supply is expensive. A pair of IRF530s can easily give us 100 watts or nearabouts.
- f

On Mon, Oct 19, 2020 at 2:47 PM iz oos <and2oosiz2@...> wrote:
Yes, 100w is what the market wants. Because... It drives well the OM2500...

Il lun 19 ott 2020 10:26 AM Murray Wills (ZL2IQ) <murray@...> ha scritto:

It sure would sell well.

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Gordon Gibby via groups.io
Sent: Monday, 19 October 2020 9:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Suggestion for the NEW UBITX V7.

 

The market likes 100 W output.  

 

In large amplifiers, the price is typically two dollars per watt output. 

 

If someone could come up with a 100 W output amplifier, separate cabinet, connects easily to a QRP rig for $200, I think it would sell pretty well

 

50 W at $100 would also sell pretty well.  

 

My 2 cents worth

 

Gordon

 

 

 



On Oct 19, 2020, at 02:00, Ashhar Farhan <farhanbox@...> wrote:



 I wonder how many want higher output. The same IRF510 pair with 25v on the drains can easily push out 40 watts. They will need beefier heatsinks.

The real is the power supply. At present a 7812 regulator can run the ubitx.

At 50 watts output, we are looking at 12v/10A or a 24v/5A supply. Will it be worth the investment to go for that? Power supply is the challenge.

I have looked at PC SMPSs. The ATX supply can provide this juice. However, it is noisy. The noise sidebands extend quite a bit. The other option is a laptop power unit, it supplies 65 watts at 19v, it can power upto 30 watts of RF output.

The real beast would be using the MRF101AN, it costs 20 dollars and puts out very low distortion 100 watts. It needs a 50v supply with 2.5Amps. 

Sigh, can anyone here design an Arduino based smps for us all? Seriously.

 

On Mon 19 Oct, 2020, 6:25 AM KD2QMZ, <syracusepro@...> wrote:

Any plans for a higher output transceiver with filtering etc, 160-6 for example?

 

 

On Sun, Oct 18, 2020, 3:32 PM Ashhar Farhan <farhanbox@...> wrote:

I remember my first look at a factory built transceiver (otherwise, all the hams in my town had a rack full of valve equipment that often pushed out 40 watts of CW from an 807)...

Saad Ali, President of FARSI (india's equivalent of ARRL) was visiting town and he was carrying an Atlas. We strung up a dipole at a hotel's roof and he walked in with just a small bag. The grossly misnamed 'Atlas' turned out to be a box slightly smaller than a shoebox. he switched it on and just kept working station after station. No PA Load/Tuning, no preselector, no valves. Just tune and talk! 
I had to inkling of however in the world I would be able to afford anything like that. My most prized possessions were two JFETs, a 12v transistor radio power supply and a rusty iron. Looking back at the ubitx sitting on my desk, I still think I am almost there. TheAtlas-210x had 100 watts output, it had AGC, it had a punchy receiver from an all analog circuitry and a free running VFO that was bandswitched!

- f

 

On Sun, Oct 18, 2020 at 11:15 PM Vic WA4THR via groups.io <vhklein=ptd.net@groups.io> wrote:

Following the discussion about having equipment affordable by a new young ham starting the hobby, I looked back at what I paid when I first got on the air in 1964:

 

  $59.95 Knight-Kit R-55A Receiver (6 months before getting licensed, might have been a Christmas Present)

 $10.95 Knight-Kit crystal calibrator option for the R-55A, so I could get within 1kHz of a correct frequency!

 $49.95 Knight-Kit T-60 Transmitter (ordered the day my license arrived, 60w input and 20-30w output)

$120.85 Total cost spent as I already had a microphone, headphones, wire for an antenna from being a SWL

 

Equivalent today: $1,014.67 or about the price range of an IC-7300 station and needed extras

 

But, look at the current uBitX V6 for $200 that comes with all but a power supply and antenna for $200, that would have been only $24 in 1964! These wonderful radios knock down a lot of barriers to entry for the hobby! Oh what I would have given to have one of these back then...

=Vic=


Re: Rx while transmitting #ubitx

edoardo marchetti
 

Nice, so I have many options to decide!
Well, if you all are thinking radio frequency interference to be the cause of my issue, maybe is because audio cable and antenna cable are mounted in parallel to each other so, even if they are centimeters distanced, I should substitute the original antenna cable, made of two wires, with a coaxial.
I must try.
Thanks everybody!
73
IU6DBK

On Mon, 19 Oct 2020, 00:12 Bob Lunsford via groups.io, <nocrud222=yahoo.com@groups.io> wrote:
When I built the Heathkit QRP radios, they provided four 200 Ohm, 2W resistors that were paralleled for a dummy load. These were mounted on a connector that was attached to the radios' output connector.

Cheap enough. Even a very short piece of coax with a  connector already on it can be used by soldering the four resistors in parallel across the open end. No need to get fancy.

I still have the dummy load and if used only for a second or two, my 100W rig can be used and the dummy load gets warm...enough to touch with no problem.

On Sunday, October 18, 2020, 5:01:15 PM EDT, edoardo marchetti <mentorade@...> wrote:


I have no dummy load... I know, I should make our buy one.
Thanks for answering my question
IU6DBK

On Sun, 18 Oct 2020, 22:54 Evan Hand, <elhandjr@...> wrote:
Does the feedback happen when connected to a dummy load?

73
Evan
AC9TU


Re: Suggestion for the NEW UBITX V7.

Ashhar Farhan
 

More than market, is that what we would personally want? As I said, the hidden cost really is the power supply. A 200 watts power supply is expensive. A pair of IRF530s can easily give us 100 watts or nearabouts.
- f

On Mon, Oct 19, 2020 at 2:47 PM iz oos <and2oosiz2@...> wrote:
Yes, 100w is what the market wants. Because... It drives well the OM2500...

Il lun 19 ott 2020 10:26 AM Murray Wills (ZL2IQ) <murray@...> ha scritto:

It sure would sell well.

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Gordon Gibby via groups.io
Sent: Monday, 19 October 2020 9:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Suggestion for the NEW UBITX V7.

 

The market likes 100 W output.  

 

In large amplifiers, the price is typically two dollars per watt output. 

 

If someone could come up with a 100 W output amplifier, separate cabinet, connects easily to a QRP rig for $200, I think it would sell pretty well

 

50 W at $100 would also sell pretty well.  

 

My 2 cents worth

 

Gordon

 

 

 



On Oct 19, 2020, at 02:00, Ashhar Farhan <farhanbox@...> wrote:



 I wonder how many want higher output. The same IRF510 pair with 25v on the drains can easily push out 40 watts. They will need beefier heatsinks.

The real is the power supply. At present a 7812 regulator can run the ubitx.

At 50 watts output, we are looking at 12v/10A or a 24v/5A supply. Will it be worth the investment to go for that? Power supply is the challenge.

I have looked at PC SMPSs. The ATX supply can provide this juice. However, it is noisy. The noise sidebands extend quite a bit. The other option is a laptop power unit, it supplies 65 watts at 19v, it can power upto 30 watts of RF output.

The real beast would be using the MRF101AN, it costs 20 dollars and puts out very low distortion 100 watts. It needs a 50v supply with 2.5Amps. 

Sigh, can anyone here design an Arduino based smps for us all? Seriously.

 

On Mon 19 Oct, 2020, 6:25 AM KD2QMZ, <syracusepro@...> wrote:

Any plans for a higher output transceiver with filtering etc, 160-6 for example?

 

 

On Sun, Oct 18, 2020, 3:32 PM Ashhar Farhan <farhanbox@...> wrote:

I remember my first look at a factory built transceiver (otherwise, all the hams in my town had a rack full of valve equipment that often pushed out 40 watts of CW from an 807)...

Saad Ali, President of FARSI (india's equivalent of ARRL) was visiting town and he was carrying an Atlas. We strung up a dipole at a hotel's roof and he walked in with just a small bag. The grossly misnamed 'Atlas' turned out to be a box slightly smaller than a shoebox. he switched it on and just kept working station after station. No PA Load/Tuning, no preselector, no valves. Just tune and talk! 
I had to inkling of however in the world I would be able to afford anything like that. My most prized possessions were two JFETs, a 12v transistor radio power supply and a rusty iron. Looking back at the ubitx sitting on my desk, I still think I am almost there. TheAtlas-210x had 100 watts output, it had AGC, it had a punchy receiver from an all analog circuitry and a free running VFO that was bandswitched!

- f

 

On Sun, Oct 18, 2020 at 11:15 PM Vic WA4THR via groups.io <vhklein=ptd.net@groups.io> wrote:

Following the discussion about having equipment affordable by a new young ham starting the hobby, I looked back at what I paid when I first got on the air in 1964:

 

  $59.95 Knight-Kit R-55A Receiver (6 months before getting licensed, might have been a Christmas Present)

 $10.95 Knight-Kit crystal calibrator option for the R-55A, so I could get within 1kHz of a correct frequency!

 $49.95 Knight-Kit T-60 Transmitter (ordered the day my license arrived, 60w input and 20-30w output)

$120.85 Total cost spent as I already had a microphone, headphones, wire for an antenna from being a SWL

 

Equivalent today: $1,014.67 or about the price range of an IC-7300 station and needed extras

 

But, look at the current uBitX V6 for $200 that comes with all but a power supply and antenna for $200, that would have been only $24 in 1964! These wonderful radios knock down a lot of barriers to entry for the hobby! Oh what I would have given to have one of these back then...

=Vic=

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