Date   
Re: knq7a bias current

Ronald Hering
 

I did some more checking and changed the 510, the gate voltage goes to 2.2 volts on keying and the drain drops to around 10 volts all other voltages arereal close to the chart.
--------------------------------------------

On Sat, 10/21/17, Adam Rong rongxh@... [CHINA_QRP] <CHINA_QRP@...> wrote:

Subject: Re: [CHINA_QRP] knq7a bias current
To: CHINA_QRP@...
Date: Saturday, October 21, 2017, 10:40 AM


 












Ron,



Have you observed very hot parts during transmission?
Besides the
trimmer position, please check if you have properly
installed the
insulators for BD139/D882 and IRF510.



Thanks,

Adam



于 2017-10-21 23:28, rhering6938@...
[CHINA_QRP] 写道:



 


Hi All,

Finally getting around to finishing my knq7,
but ran into
a problem.

 The idle current is around 40 ma but when
PTT is keyed it
jumps up to around 1400ma at the low end. Any
ideas on
where to start looking? All help will be
greatly
appreciated. Thanks, Ron.
























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Re: knq7a bias current

kb1gmx@...
 

The drain should be very near the power supply voltage if its dropping its either a 
problem with the meter going nuts from RF (They do that!) or your power supply 
is weak.

The gate voltage for the final will vary from device to device for a given drain 
current.  I've seen 2-3V typical across a lot of IRF510s (I use them for a lot of stuff).

Other reasons for increased drain on TX is, final is oscillating, or carrier leakage.
The latter can be due to an error around the NE602 (U3 on some schematics).
If the device is unbalanced due to a misplaced part of other short or leakage
it will emit carrier and that will show RF power (maybe milliwatts) output and 
increased drain.  Also if the carrier frequency adjustment is way off you may 
not be on the edge of the filter pass band and instead you can be inside the
passband.  That can also contribute excess carrier at output.

Just a few thoughts.

Allison

Re: CS-Series IF

kb1gmx@...
 

Here in the USA 9MHZ crystals are common.  I've built many filter using them. 
however ladder filter like in KNQ7A and others will cave a center frequency
slightly lower than 9mhz (using rocks that test at 9mhz, my filters are more like
8.997 to 8.9985mhz center frequency.)  though for this use that should be ok.

You will have to workout the capacitor values to use for that set of crystals.


Allison/Kb1GMX

Re: Frequency Display for Sandwich

n7rgw
 

I have now decided to make the faceplates for all three of these options available, LCD, Larger OLED and Small OLED display.  The cost is $8 per plate plus shipping.  Both front and back plates are available for the LCD kit at $14 the pair.  Options are, matted finish, glossy finish and glossy with white letters depending on my stock.  PayPal: larry@....  Please specify finish and faceplate.  US shipping is $3.00.
The complete kit for the small and larger OLED are $30 each.

8% off for CS Series SSB kit

Adam Rong
 

Gang,

As the year end comes, we will provide 8% off promotion for CS-series
kit only from now on to the end of this year.

Place online order through:
http://crkits.com

Thanks,
Adam

knq7a output signal

Ronald Hering
 

Hi Again,
I was aligning the tx section of my rig and don't have a watt meter for 20 meters so I put a scope probe on the antenna, the envelope measured 6 volts p-p. Is that about right or do i really need a watt meter? All voltages measure good, had to replace the 3357, shorted B-C. Thanks Ron


Re: knq7a output signal

John Landry
 

Ron,

This online calculator might be helpful:


73,

John
AA7US

---In CHINA_QRP@..., <rhering6938@...> wrote :

Hi Again,
I was aligning the tx section of my rig and don't have a watt meter for 20 meters so I put a scope probe on the antenna, the envelope measured 6 volts p-p. Is that about right or do i really need a watt meter? All voltages measure good, had to replace the 3357, shorted B-C. Thanks Ron


knq7a output envelope

Ronald Hering
 

Hi all,
 I finally got the bias voltage right ( had a shorted 3357 ), now , not having a rf meter for 20 meters, I hung a scope on the antenna. I could only peak for 6 volts p-p, all the 530 voltages ars correct. Is what im seeing on the scope right or do i need to find an rf meter? Thanks ron


Re: knq7a output envelope

kb1gmx@...
 

Way low.

6V PP translates to 4.242V rms (Vp-p*.707) across 50 ohms or .08484A (ohms law)
and the power is RMS voltage * current or about .35W  not the nominal 6-10W
at nominal 13.8V.

I'd expect the RMS voltage for full power to be more than 17-20V RMS or about 
25 to 29V P-P.

The other thing to monitor is the current of the radio during transmit.  It should reach
2A (24-27W DC input) during normal operation.



Allison

New Products Plan - NP0 or C0G monolithic capacitors

Adam Rong
 

Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam

Re: New Products Plan - NP0 or C0G monolithic capacitors

JOHN CRONHELM
 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam


Re: New Products Plan - NP0 or C0G monolithic capacitors

Adam Rong
 


Would 10 each of these values good for you? I will ask for $5 for each set of total 100 pcs and the shipping cost would be $5 each time.

15pF
22pF
27pF
47pF
100pF
150pF
220pF
270pF
470pF
820pF

Thanks,
Adam

2017年12月14日 08:11,"John Cronhelm johncronhelm@... [CHINA_QRP]" <CHINA_QRP@...>写道:

 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam


Re: New Products Plan - NP0 or C0G monolithic capacitors

JOHN CRONHELM
 

Thanks for letting me know the values you are offering.
None required at the present.

On Thursday, December 14, 2017, 12:54 PM, Adam Rong rongxh@... [CHINA_QRP] wrote:

 


Would 10 each of these values good for you? I will ask for $5 for each set of total 100 pcs and the shipping cost would be $5 each time.

15pF
22pF
27pF
47pF
100pF
150pF
220pF
270pF
470pF
820pF

Thanks,
Adam

2017年12月14日 08:11,"John Cronhelm johncronhelm@... [CHINA_QRP]" <CHINA_QRP@...>写道:
 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam


Re: New Products Plan - NP0 or C0G monolithic capacitors

Adam Rong
 

Guys,

I will offer another assortment at the same price. Please contact offline. I have ordered the parts and will ship next Monday if everything is smooth.

5.1pF
10pF
18pF
33pF
39pF
68pF
82pF
120pF
390pF
560pF

Thanks,
Adam

在 2017年12月15日,上午12:24,Adam Rong <rongxh@...> 写道:


Would 10 each of these values good for you? I will ask for $5 for each set of total 100 pcs and the shipping cost would be $5 each time.

15pF
22pF
27pF
47pF
100pF
150pF
220pF
270pF
470pF
820pF

Thanks,
Adam

2017年12月14日 08:11,"John Cronhelm johncronhelm@... [CHINA_QRP]" <CHINA_QRP@...>写道:
 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam




Re: New Products Plan - NP0 or C0G monolithic capacitors

Adam Rong
 

Guys,

This afternoon, I received 20 values of capacitors (total 10,000 capacitors), and I spent about 3 hours to kit for 5 customers. I am pleased to see these shining new "Green Beans" will be shipped tomorrow.

Instead of counting them, I weigh them. I found that different value has different unit weight, so I have to record the unit weight into a table. Next time, I should be able to kit faster.

Hope you enjoy the beans.

Thanks,
Adam



在 2017年12月15日,上午9:43,Adam Rong <rongxh@...> 写道:

Guys,

I will offer another assortment at the same price. Please contact offline. I have ordered the parts and will ship next Monday if everything is smooth.

5.1pF
10pF
18pF
33pF
39pF
68pF
82pF
120pF
390pF
560pF

Thanks,
Adam

在 2017年12月15日,上午12:24,Adam Rong <rongxh@...> 写道:


Would 10 each of these values good for you? I will ask for $5 for each set of total 100 pcs and the shipping cost would be $5 each time.

15pF
22pF
27pF
47pF
100pF
150pF
220pF
270pF
470pF
820pF

Thanks,
Adam

2017年12月14日 08:11,"John Cronhelm johncronhelm@... [CHINA_QRP]" <CHINA_QRP@...>写道:
 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam





NorCal 40 digital VFO version on Choc perfboard

Adam Rong
 

Gang,

Job is done. I get full 40-meter coverage without birdie on 7.023 MHz because my digital VFO outputs operating frequency plus BFO frequency. The bandwidth of the crystal filter seems a bit wide and I will figure out later once I have time.

The sidetone is pure but a bit low. I will adjust the frequency delta later. The RF output is 1.2 watt. Not very good but acceptable because I replaced the PA transistor with a BD139, very cheap one. 

I believe the modification of NC40A is very necessary to fix my issues. As an experiment, I am quite satisfied with what I have now.

Thanks,
Adam

Re: New Products Plan - NP0 or C0G monolithic capacitors

Adam Rong
 

Gang,

Merry Christmas!

I have shipped all the cap orders with a small gift. You can make an oscillator or even a Pixie2. Enjoy.

Thanks,
Adam

2017年12月15日 09:43,"Adam Rong" <rongxh@...>写道:

Guys,

I will offer another assortment at the same price. Please contact offline. I have ordered the parts and will ship next Monday if everything is smooth.

5.1pF
10pF
18pF
33pF
39pF
68pF
82pF
120pF
390pF
560pF

Thanks,
Adam


在 2017年12月15日,上午12:24,Adam Rong <rongxh@...> 写道:


Would 10 each of these values good for you? I will ask for $5 for each set of total 100 pcs and the shipping cost would be $5 each time.

15pF
22pF
27pF
47pF
100pF
150pF
220pF
270pF
470pF
820pF

Thanks,
Adam

2017年12月14日 08:11,"John Cronhelm johncronhelm@... [CHINA_QRP]" <CHINA_QRP@...>写道:
 

Hi Adam,
Any chance you can send out
Smaller quantities of monolithic capacitors. May need some later but not right now.
John Vo1jcc.

On Dec 13, 2017 12:48 PM, "Adam Rong rongxh@... [CHINA_QRP]" <CHINA_QRP@...> wrote:
 


Gang,

Recently a famous QRPer in United States wrote to me looking for a good source of NP0 or C0G monolithic capacitors for VFO, and my recommendation is the light green capacitors that I have been using in my kits. It has a small Torch marking on the body. It is the best brand in China and the local price is about 2~3 times higher than other brands.

For the C0G or NP0, 5% tolerance, 100 volt type, it is good for both VFO and LPF purposes. The MOQ in China is 500 pcs, but I would like to split it into 100 pcs, asking for 5 USD not including shipping. C0G or NP0 capacitor value is no greater than 820 pF. Please let me know if you are interested, and the values you are looking for. Thank you.

Thanks,
Adam





Re: New Products Plan - NP0 or C0G monolithic capacitors

John Landry
 

Hi Adam,

Merry Christmas to you and everyone here in the China QRP group.

73,

John
AA7US


---In CHINA_QRP@..., <rongxh@...> wrote :

Gang,

Merry Christmas!

I have shipped all the cap orders with a small gift. You can make an oscillator or even a Pixie2. Enjoy.

Thanks,
Adam

An idea of a charity project

Adam Rong
 

Gang,

This is my post on qrp-tech. Please comment.

A few days ago, an American ham wrote to me asking for donation of my single band SSB transceiver fully assembled. He wrote, I am interested in your mono band transceivers. I am disabled, low income and cannot build one. I wrote back to him to make sure he was serious, and worked with my US partner Larry to build a radio for him. I told Larry that it might be a good idea to start a project called "Donate a radio each year", and he agreed.

Just now, I had some email exchange with Chuck and I had a better idea on this. We can start a charity project to donate kits and distribute these kits for free. As a return, people can donate some money back to this project to make the project go on. As a starting point, I will donate about 20 NC40A kits to Chinese hams and will ask someone with good reputation to keep the money and run the project. I believe the project can expand to the worldwide, because I believe we have good supply chain here in China, and you have great designs, and both countries have people need help, so we can cooperate somehow.

Although it is for good cause, we still need to respect the copyright or design, so we need to ask for permission from the designer. Also, we don't want to compete with commercial projects, because it is not good for this ever shrinking QRP community.

It is still a very immature idea, but I'd like to hear from you guys.

Thanks,
Adam

Update to frequency display for CS-Series radio

n7rgw
 

I have added a summary of my experiments with the KN-Q7A and CS-Series radio using the Sandwich VFO.

Thought you might enjoy the read.  This discusses the latest modification to the Arduino Sketch to enable the OLED frequency display as well as the Dual-Band feature upgrades to the basic radio.