Date   
Re: BITX20 KIT

ki6ds@...
 

Horey, thank you for your kind words of encouragement. We are very close
to testing the board layout. As soon as we prove the board, I will order
the parts and the first 100 boards. It will take about 2 weeks to get the
boards, and during that time I will be makeing up parts kits. I think
that we could possibly be shipping kits by March 1st, if we don't run into
any problems.

I agree that there definitely is a void in the kit world for a SSB kit
that is reasonably priced. I am able to kit it for a low price because I
buy in large volumes, and I did not take my usual markup on this kit to
enable more people to be able to afford it. Again, thank you for the kind
words. Doug, KI6DS

BITX20Hi Doug

That would be a tremendous achievement. There are a lot of CW kits but not
a single SSB radio in kit form apart from the one that Small Wonder Labs
has stopped making and the K2 which is beyond our reach. Here in Calcutta
there is tremendous interest in the same and we will be looking forward to
your launch and sure to procure dozens of the same.

73

Horey, VU2HFR
General Secretary
Bengal Amateur Radio Society



BITX20 KIT

Nilanjan Majumdar
 

BITX20Hi Doug

That would be a tremendous achievement. There are a lot of CW kits but not a single SSB radio in kit form apart from the one that Small Wonder Labs has stopped making and the K2 which is beyond our reach. Here in Calcutta there is tremendous interest in the same and we will be looking forward to your launch and sure to procure dozens of the same.

73

Horey, VU2HFR
General Secretary
Bengal Amateur Radio Society

Re: BITX20 Kit Coming

vk3bfa <woofferau@...>
 

--- In BITX20@..., "KI6DS" <ki6ds@...> wrote:

I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20.
That would be truly excellent - hopefully we will be able to find some
way of working around the horrible postal and payment barriers that
are such a pain between Australia and the US. Perhaps I could kit them
here for the K-ZL market - (email me if interested) happy to do it at
cost, this is a lovely little radio (yet to finish mine) and a kit
would encourage so many people to the joy of being able to say on air

"Built the rig myself om..."

Andrew VK3BFA.

Re: BITX20 Kit Coming

qrpjl1kra
 

Hi, All

I would like to announce to the group that my company, Hendricks
QRP
Kits will be coming out with a kit to build the BITX20.
This is very good news.
PE1ICQ Arno, who also planned BITX board kindly forward
this information to me. Thank you Arno.

I am satisfied with the Epiphyte 3.5MHz SSB transceiver
by Doug and Nocal colleague. Unfortunately they are no more
in distribution due to obsolete of cheap Japanese 455kHz filter.

BITX without special parts is long long lasting design and
the design advantage reflected to the Doug's attractive
target price.

Bit tired with CW-only transceiver, but still no time to
gather whole BITX parts from market. Thanksful to
Norcal kitting technique maintained in QRP community.
I am sure to take Doug Hendrics' BITX distribution.

JL1KRA Junichi

Re: BITX20 Kit Coming

Jamie
 

I will be interested in purchasing a kit as well.

Jamie/VE3GXQ

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf
Of KI6DS
Sent: Wednesday, January 17, 2007 2:04 AM
To: BITX20@...
Subject: [BITX20] BITX20 Kit Coming



I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS

Re: BITX20 Kit Coming

Tim A. King, Jr. <ag4rz@...>
 

Please let us know when they are ready....I will gladly order a couple of kits, if not more!!!!!

Tim
AG4RZ

----- Original Message -----
From: KI6DS
To: BITX20@...
Sent: Wednesday, January 17, 2007 2:03 AM
Subject: [BITX20] BITX20 Kit Coming


I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS






------------------------------------------------------------------------------


No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.432 / Virus Database: 268.16.12/631 - Release Date: 1/16/2007 8:25 AM

BITX20 Kit Coming

John KG9DK
 

I will be interested in a kit verison too. In time you may offer
different bands or a mulit band BITX-xx. Good luck.
John
kg9dk

Re: BITX20 Kit Coming

ki6ds@...
 

We will start with 20 Meters. I am sure that we can do other bands later
but I want to get started on 20 first. 72, Doug


Thank you for that good BITX20 kit.
And what about a BITX40 ? In my country (Turkia) permitted only 40m and
10m
QRP homebrew rigs (with a TB type lisance of course)
Tnx & 73




Re: BITX20 Kit Coming

Bay Mete
 


Thank you for that good BITX20 kit.
And what about a BITX40 ? In my country (Turkia) permitted only 40m and 10m
QRP homebrew rigs (with a TB type lisance of course)
Tnx & 73

Re: BITX20 Kit Coming

ki6ds@...
 

Rahul, it is very good to hear from you. You are the very first to
acknowledge receipt of a NorCal 20. That was a wonderful project but very
difficult to do. This one will go much better. I really admire how you
guys were able to come up with a design and then scrounge the needed parts
from TV's etc. True ingenuity. The new kit should encourage lots of
others to build the radio, as all of the parts are there. 72, Doug

Hi! Doug & others,
This is great news. Many friends had asked for boards and other stuff
but we were unable to provide for the lack of infrastructure and time to
manage the whole project. I am happy this would benefit so many of our
friends across the world.
With Doug at helms of affairs I am certain it would be huge success. BTW
thanks to to Norcal for the NC20s sent to VUs thru Rev Dobbs, I am
modding mine for SSB after excellent writeup on the K1 SSB mod.
TNX & All the best for the good cause.
73
Rahul VU3WJM


KI6DS <ki6ds@...> wrote:
I would like to announce to the group that my company, Hendricks
QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS






---------------------------------
Inbox full of unwanted email? Get leading protection and 1GB storage with
All New Yahoo! Mail.



Re: BITX20 Kit Coming

Rahul Srivastava
 

Hi! Doug & others,
This is great news. Many friends had asked for boards and other stuff but we were unable to provide for the lack of infrastructure and time to manage the whole project. I am happy this would benefit so many of our friends across the world.
With Doug at helms of affairs I am certain it would be huge success. BTW thanks to to Norcal for the NC20s sent to VUs thru Rev Dobbs, I am modding mine for SSB after excellent writeup on the K1 SSB mod.
TNX & All the best for the good cause.
73
Rahul VU3WJM


KI6DS <ki6ds@...> wrote:
I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS






---------------------------------
Inbox full of unwanted email? Get leading protection and 1GB storage with All New Yahoo! Mail.

Re: BITX20 Kit Coming

Scott <falconsl@...>
 

The kit will be an asset to us that are less experienced. I will
purchase a couple for myself. One will be used to try some of the mods
that are posted one this group. I believe having a finished product
will also help me with the one I am trying to build now. hopefully in
a few weeks I will be posting a very ugly picture of my first module.

Scott

--- In BITX20@..., "KI6DS" <ki6ds@...> wrote:

I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS

Re: BITX20 Kit Coming

ragavan
 

WOW!

Thats Great News to Many!In VU Land Torroids And Air Variables are a
Real Pain to find....But that shouldnt be a problem in your case...
I am working(almost) on the BITX 20 And should be on Air Soon....

The tips on your site are really neat for the novice as well as the
advanced homebrewer.......

I still use that resistor bending technique..it gives real nice
results....

Keep up the good work!!

best 73,

Ragav
VU3VWR

--- In BITX20@..., "KI6DS" <ki6ds@...> wrote:

I would like to announce to the group that my company, Hendricks
QRP
Kits will be coming out with a kit to build the BITX20. Dan
Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The
board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3.
We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the
design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the
list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim
Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been
involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS

BITX20 Kit Coming

KI6DS <ki6ds@...>
 

I would like to announce to the group that my company, Hendricks QRP
Kits will be coming out with a kit to build the BITX20. Dan Tayloe,
N7VE has layed out a pcboard from the schematic for Version 3 that
is on this site. Dan and I decided to make a few changes to the
schematic in order to make it more cost effective to kit. The board
and kit will use toroids and trimcaps in place of the hose washers
and the 10.7 MHz. cans. The kit will have a commercial quality
board, double sided, silk screened, soldermasked and plated
through. The kit will come with all board mounted parts. The
builder will need to supply their own case, microphone, connectors
and a 365pF air variable. We plan on using 10 MHz. for an IF. The
focus of this kit is to enable builders to get all the parts needed
in 1 place to build the basic radio. I am hoping to sell the kit
for $35 including the board and parts. Dan has suggested and I
agreed to the addition of diode protection on the power input, and
also added another section to the output filter in order to make
sure that it meets FCC specs, but other than those 2 additions, the
schematic we used to develop the board is the same as Version 3. We
are not trying to change the design, we just wanted to accept the
offer to develop a kit.

Here is where we are now. The board is done and at the board
house. I have placed an order for 3 sets of prototype parts. I
will kit them, and we will build up the three prototype boards to
check out the layout and see how it works. Once we prove the design
of the board, we will be ready to sell kits. When I am ready to
start accepting orders I will post here first. The first run will
be 100 kits. The size of the board is 3.5 x 5"

Hopefully there will be some interest in the kit and it will
encourage more people to build this great little rig. The thing
that attracted me to the BITX20 is that I feel that it is the
successor to the Epiphyte, which was developed by Derry Spittle,
VE7QK and I was on the team that helped kit it for NorCal. The
problem with the Epiphyte was that it used some esoteric parts that
are almost impossible to get. When I discovered the BITX20 used
commonly available parts, I was really excited. Thanks to all who
have worked to make the kit what it is. It is my aim to keep the
cost of the kit low so that it remains attractive to builders and
new hams.

We will be posting pictures and schematics as we progress. The
boards are due to arrive a week from Friday. I will update the list
when that happens.

By the way, a little about me. I have been interested in QRP for
the past 30 years, and cofounded the NorCal QRP Club with Jim Cates,
WA6GER (SK) in 1993. NorCal has kitted and produced over 40 kits
since that time and has sold over 20,000 kits. I have been involved
in every one of them. I started my own kit company, Hendricks QRP
Kits about a year ago. I am close to retirement from my teaching
job, and plan on using the company to keep me busy during
retirement. Check out my website at www.qrpkits.com

Hopefully, Ashhar and the others who have done so much work on this
design will be happy with our work.
72, Doug, KI6DS

Re: BITX 20 RF final power output

bkopski <kopskirl@...>
 

Farhan, et al -

Thanks everyone for the inputs. I have methodically followed all the
suggestions that I could with no success. I also touched base with
Wes, W7ZOI since the same PA is discussed in EMRFD. The summary at this
point is that more power than my limited 1 watt should be possible -
certainly several folks have achieved several watts - but for now I am
"stuck". Rather than get completely bogged down with this one issue,
I'm going to pause here and box up all the transceiver subassys
presently spread over my bench, and try to get on the air. Besides, in
one way or another all the functional blocks - now including the PA -
could stand some further refinement anyway. But for now - after all the
building - I'm anxious and in desparate need of a QSO - which will be my
first ever on HF - despite having my ticket since 1957! The BITX idea
was the impetus for me to pursue this goal.

Thank You all again,

73,

Bob, K3NHI





--- In BITX20@..., farhan@... wrote:


The IRF510 is not really meant to be a RF power device that exhibits
linear behaviour. Its original job is to provide very high efficiency
switching at medium frequencies (a couple of hundred KHz).

Hence, IRF510 will always be a hack.

There are a couple of things that one has to be careful about:

1. the oscillations that the IRF510 gives are usually multi-stage
problem.
The most effective thing is to really build comparments of PCBs around
each stage within the power chain.

2. It is probably a good idea to add another stage of amplification
between the prediver and the driver stage and introduce 6db
attentuation pads inter-stage (except between the 2N2218 and the
IRF510). This provides
proper termination to all stages.

3. Each stage in the power chain needs to be decoupled from the other
with
chokes on the power line.

4. Build the RF power chain on a separate board.

While all of these together will surely cure the instability, a few of
them at a time usually suffice. I didnt build all of this into the
original as it would have made the power chain as complicated (if not
more) than the exicter.

You should also look at exploring other options for the power chain:
from
simply plugging in an RF module(ugh!) to some really cool alternatives
that range from QRP finals like SM0VPO's 0.5W linear
(http://web.telia.com/~u85920178/index.htm) to an 807 valve based
linear (
dont have the URL with me right now but any 1970s ARRL/RSBG handbook
should have all the details).

- farhan

On Mon, 8 Jan 2007, market10gardener wrote:

Hi Bob,
If you are still looking for reassurance that the PA as described
will
give 6 Watts output, I can confirm that this has been my experience.
It
is some time now since it was built but my main problem was in
taming
the IRF 510 stage. Message 438 refers to this. Since then I tried
several different T1 configurations, including Farhan's original tap
washer with 40 turns bifilar wound. The picture in the photos
section
(PA module on a heat sink above and behind the VFO) shows a version
with 2 ferrite toroids stuck together and the present arrangement
which seems to be marginally the most effective is 8 turns 24 swg
bifilar wound on a single FT37-43 core. Each of the 3 leads coming
from
it is threaded through its own miniature ferrite bead. All of these
transformers worked and I can get a little more than 7 Watts. By the
way I did also test the rig on the air with just the 2N2218 stage
connected directly to the LPF and had several good contacts around
Europe with 100mW or so. A balanced 50 Ohm antenna helps stability.
As
stated elsewhere beware of killing the IRF 510 by momentary shorting
of
its leads with the power on!
John G0UCP

Re: supplier of XTAL's in the U.S. ?

iyung_w <iyung_w@...>
 

Good soure of toroids:

http://www.partsandkits.com/toroids.asp

rgds
julius

--- In BITX20@..., "sg2112" <SG2112@...> wrote:

They are matched more than well enough for SSB bandwidth filters, I
have a set of 10 Mhz ones in a homebrew 80M SSB receiver ... If I
remember right they were all within 50Hz of each other

I also got 40 9.6 Mhz crystals from him real cheap and managed to
get
one 8 pole CW filter matched within 10 hz and two 8 pole SSB filters
one mathced within 20 Hz and one matched within 25 hz .... Q is not
as
good as I'd prefer but they aren't too bad

Not bad for 20/1.00 crystals .....

JR

--- In BITX20@..., "ve3xj" <ve3xj@> wrote:

I noticed that Dan's Small Parts sells a matched set of six 10
Mhz
crystals for $US6. Has anyone tried these to see if indeed they
are
matched? I would tend to order two sets to see if this is indeed
the
case. I also scrolled through and there are a number of parts
that
have potential. He also has {quote}:

"10:7 MHZ IF CAN. PART NO.IF123 See can, bottom row to right in
pic.
above.
These are the 10.7 MHZ cans that are used in the Neophyte, NNIG
RIG,
and other rigs and projects out there.

PRICE..$1.65 EA."

Would these work also?

The web page is http://www.danssmallpartsandkits.net/

73

Jim, VE3XJ



--- In BITX20@..., "Scott" <falconsl@> wrote:


Where is everyone getting the crystals in the U.S. ?

Also the 10mm tunable coils? I found some on ebay.


Thanks Scott

Re: BITX 20 RF final power output

farhan@...
 

The IRF510 is not really meant to be a RF power device that exhibits linear behaviour. Its original job is to provide very high efficiency switching at medium frequencies (a couple of hundred KHz).

Hence, IRF510 will always be a hack.

There are a couple of things that one has to be careful about:

1. the oscillations that the IRF510 gives are usually multi-stage problem. The most effective thing is to really build comparments of PCBs around each stage within the power chain.

2. It is probably a good idea to add another stage of amplification between the prediver and the driver stage and introduce 6db attentuation pads inter-stage (except between the 2N2218 and the IRF510). This provides proper termination to all stages.

3. Each stage in the power chain needs to be decoupled from the other with chokes on the power line.

4. Build the RF power chain on a separate board.

While all of these together will surely cure the instability, a few of them at a time usually suffice. I didnt build all of this into the original as it would have made the power chain as complicated (if not more) than the exicter.

You should also look at exploring other options for the power chain: from simply plugging in an RF module(ugh!) to some really cool alternatives that range from QRP finals like SM0VPO's 0.5W linear (http://web.telia.com/~u85920178/index.htm) to an 807 valve based linear ( dont have the URL with me right now but any 1970s ARRL/RSBG handbook should have all the details).

- farhan

On Mon, 8 Jan 2007, market10gardener wrote:

Hi Bob,
If you are still looking for reassurance that the PA as described will
give 6 Watts output, I can confirm that this has been my experience. It
is some time now since it was built but my main problem was in taming
the IRF 510 stage. Message 438 refers to this. Since then I tried
several different T1 configurations, including Farhan's original tap
washer with 40 turns bifilar wound. The picture in the photos section
(PA module on a heat sink above and behind the VFO) shows a version
with 2 ferrite toroids stuck together and the present arrangement
which seems to be marginally the most effective is 8 turns 24 swg
bifilar wound on a single FT37-43 core. Each of the 3 leads coming from
it is threaded through its own miniature ferrite bead. All of these
transformers worked and I can get a little more than 7 Watts. By the
way I did also test the rig on the air with just the 2N2218 stage
connected directly to the LPF and had several good contacts around
Europe with 100mW or so. A balanced 50 Ohm antenna helps stability. As
stated elsewhere beware of killing the IRF 510 by momentary shorting of
its leads with the power on!
John G0UCP

Re: BITX 20 RF final power output

Arv Evans
 

Bob

One quick thought...you mentioned testing without the output BPF. That
may be giving you an erroneous indication. Take a look at the KA1UNW
web site

<http://pages.cthome.net/okmunwurx/>

and in particular at this URL on that site

< http://pages.cthome.net/okmunwurx/waveform.jpg>

to see what I am talking about.

Arv
_._




bkopski wrote:



Hi Arv -

Thank You for your inputs. I am "brand new" to posting/replying so
please forgive me if I don't get everything proceeduraly "right".

I am primarily seeking to know if the described 6 watts is routine
experience for BITX builders for the described design/operating
conditons. If so - then I've got something "wrong".

My driver and PA are built as individual subassemblies and are
individually testable, or in combination. (True also for ALL the other
transceiver subassys. - this is my first such HF experience and I'm
trying to learn block by block.)

I have a good 50 ohm load, power attenuator, power meter in place. I
have tried a 10 ohm parasitic suppresser in the gate lead but now will
pursue your suggestions re: beads on gate and/or drain. This may be a
key point because the drain waveform is very clean up to about +20
output but breaks up as I approach +30 (with increasing drive and/or
standing current), and trying to go past that level turns the drain
waveform to pure junk - lots of breakup - but I see no evidence of
component break down.

I have tried several output transformers and different 510's - no
significant differences.

I have reviewed messages 918 and 376.

I am aware that increasing supply voltage should allow more power but
I'm first trying to attain the described performance on 12V - and
besides - if I have something wrong more voltage would likely not be the
way to go anyway right now!

Thank You again for your interest and inputs - I'm now getting some
beads in hand.

Cordially,

Bob
--- In BITX20@yahoogroups. com <mailto:BITX20%40yahoogroups.com>, arv
evans <arvid.evans@ ...> wrote:

Bob

Some personal observations from building and debugging a BITX20 and a
BITX40:

* Preliminary RF PA testing should be done with a 50 ohm
non-inductive dummy load, not with an antenna or any external tuner.
* The RF PA should probably be inside a shielded enclosure to help
keep it's output from being coupled back into earlier stages.
* Ferrite beads and/or RL type suppressors can be used on the
IRF-510 Gate and Drain leads in stubborn cases of self oscillation.
* Not all IRF-510 devices are equal. Some work better than others.
At 12 volts we are running this device pretty near the lower level
of it's capability.
* If the RF PA stage has any potential instability, certain settings
of your antenna tuner can make it oscillate.
* The 2N2218 RF PA driver stage gain can be adjusted by changing the
6.2 ohm resistor value that is in series with the 0.1 MFD cap on
the Emitter. Be careful that you don't exceed the device maximum
ratings.
* Low gain in the microphone amplifier or a low output mike can lead
to lower than expected SSB output from the transmitter. Try
inserting a tone into the mike input and check to see if your
transmitter puts out full power that way (don't key down for very
long sessions or you may overheat something). One builder fought
low transmitter power for several weeks only to find that he had
swapped a 20 ohm resistor with a 220 ohm one in the 3-resistor
pi-net adjacent to T3.
* Look at message #918 for more information about the IRF-510 and
it's performance characteristics.
* Message #376 may be helpful.
* Make sure you have properly adjusted the BFO frequency with
respect to the IF filter passband before testing the transmitter
for maximum power output. If you Tx carrier is too far outside
the IF passband you may not get enough drive through to the final.

In the past we did talk about the need for a set of expected
measurements for signal levels throughout the whole BITX20 layout.
However I don't think that we ever got that done. Someone please
correct me if such a chart or commented schematic does exist. There
are
still new people coming on board with new BITX projects who could use
this information for troubleshooting their transceivers.

Arv
_._


bkopski wrote:


Hi All,

I've been building a "sorta-BITX 20" for the past several weeks ie.
I've
been following the very inspiring BITX design information but I've
been
incorporating some of my own ideas and preferences along the way.

I do have the receiver portion working and am now working on the
exciter/RF final amplifier portion. Here I have followed the
original
design exactly with the exception of having "real" cores available
in
substitution for the nylon washers/TV balun cores. After several
attempts/rebuilds, I've not been able to obtain the design power
output
of 6 watts - achieving only about 1-2 watts instead and this with
questionable quality (ie RE harmonics).

I'd appreciate knowing if it is your common experience with the
published BITX design to routinely attain the described output
level? I
am able to measure actual output power in dBm while driving the two
stage output amplifier as shown on Page 3 off the website. BTW - my
IRF510 final displays a power gain of 14 dB and the driver stage
displays a power gain of 23. Output of the latter is up to a solid
22
dBm so it seems like there is adaquate drive to the final device but
the
510 stage just won't deliver more than about 1-2 watts as above. It
is
as though the latter stage needs a few more dB of gain but it
already
seems to be straining to deliver quality (clean) reduced power. All
related comments/experience s are indeed appreciated, and I Thank You
in
advance.

Cordially, and 73,

Bob



Re: BITX 20 RF final power output

market10gardener <jseager@...>
 

Hi Bob,
If you are still looking for reassurance that the PA as described will
give 6 Watts output, I can confirm that this has been my experience. It
is some time now since it was built but my main problem was in taming
the IRF 510 stage. Message 438 refers to this. Since then I tried
several different T1 configurations, including Farhan's original tap
washer with 40 turns bifilar wound. The picture in the photos section
(PA module on a heat sink above and behind the VFO) shows a version
with 2 ferrite toroids stuck together and the present arrangement
which seems to be marginally the most effective is 8 turns 24 swg
bifilar wound on a single FT37-43 core. Each of the 3 leads coming from
it is threaded through its own miniature ferrite bead. All of these
transformers worked and I can get a little more than 7 Watts. By the
way I did also test the rig on the air with just the 2N2218 stage
connected directly to the LPF and had several good contacts around
Europe with 100mW or so. A balanced 50 Ohm antenna helps stability. As
stated elsewhere beware of killing the IRF 510 by momentary shorting of
its leads with the power on!
John G0UCP

Re: BITX 20 RF final power output

bkopski <kopskirl@...>
 

Hi Arv -

Thank You for your inputs. I am "brand new" to posting/replying so
please forgive me if I don't get everything proceeduraly "right".

I am primarily seeking to know if the described 6 watts is routine
experience for BITX builders for the described design/operating
conditons. If so - then I've got something "wrong".

My driver and PA are built as individual subassemblies and are
individually testable, or in combination. (True also for ALL the other
transceiver subassys. - this is my first such HF experience and I'm
trying to learn block by block.)

I have a good 50 ohm load, power attenuator, power meter in place. I
have tried a 10 ohm parasitic suppresser in the gate lead but now will
pursue your suggestions re: beads on gate and/or drain. This may be a
key point because the drain waveform is very clean up to about +20
output but breaks up as I approach +30 (with increasing drive and/or
standing current), and trying to go past that level turns the drain
waveform to pure junk - lots of breakup - but I see no evidence of
component break down.

I have tried several output transformers and different 510's - no
significant differences.

I have reviewed messages 918 and 376.

I am aware that increasing supply voltage should allow more power but
I'm first trying to attain the described performance on 12V - and
besides - if I have something wrong more voltage would likely not be the
way to go anyway right now!

Thank You again for your interest and inputs - I'm now getting some
beads in hand.

Cordially,

Bob
--- In BITX20@..., arv evans <arvid.evans@...> wrote:

Bob

Some personal observations from building and debugging a BITX20 and a
BITX40:

* Preliminary RF PA testing should be done with a 50 ohm
non-inductive dummy load, not with an antenna or any external tuner.
* The RF PA should probably be inside a shielded enclosure to help
keep it's output from being coupled back into earlier stages.
* Ferrite beads and/or RL type suppressors can be used on the
IRF-510 Gate and Drain leads in stubborn cases of self oscillation.
* Not all IRF-510 devices are equal. Some work better than others.
At 12 volts we are running this device pretty near the lower level
of it's capability.
* If the RF PA stage has any potential instability, certain settings
of your antenna tuner can make it oscillate.
* The 2N2218 RF PA driver stage gain can be adjusted by changing the
6.2 ohm resistor value that is in series with the 0.1 MFD cap on
the Emitter. Be careful that you don't exceed the device maximum
ratings.
* Low gain in the microphone amplifier or a low output mike can lead
to lower than expected SSB output from the transmitter. Try
inserting a tone into the mike input and check to see if your
transmitter puts out full power that way (don't key down for very
long sessions or you may overheat something). One builder fought
low transmitter power for several weeks only to find that he had
swapped a 20 ohm resistor with a 220 ohm one in the 3-resistor
pi-net adjacent to T3.
* Look at message #918 for more information about the IRF-510 and
it's performance characteristics.
* Message #376 may be helpful.
* Make sure you have properly adjusted the BFO frequency with
respect to the IF filter passband before testing the transmitter
for maximum power output. If you Tx carrier is too far outside
the IF passband you may not get enough drive through to the final.

In the past we did talk about the need for a set of expected
measurements for signal levels throughout the whole BITX20 layout.
However I don't think that we ever got that done. Someone please
correct me if such a chart or commented schematic does exist. There
are
still new people coming on board with new BITX projects who could use
this information for troubleshooting their transceivers.

Arv
_._


bkopski wrote:


Hi All,

I've been building a "sorta-BITX 20" for the past several weeks ie.
I've
been following the very inspiring BITX design information but I've
been
incorporating some of my own ideas and preferences along the way.

I do have the receiver portion working and am now working on the
exciter/RF final amplifier portion. Here I have followed the
original
design exactly with the exception of having "real" cores available
in
substitution for the nylon washers/TV balun cores. After several
attempts/rebuilds, I've not been able to obtain the design power
output
of 6 watts - achieving only about 1-2 watts instead and this with
questionable quality (ie RE harmonics).

I'd appreciate knowing if it is your common experience with the
published BITX design to routinely attain the described output
level? I
am able to measure actual output power in dBm while driving the two
stage output amplifier as shown on Page 3 off the website. BTW - my
IRF510 final displays a power gain of 14 dB and the driver stage
displays a power gain of 23. Output of the latter is up to a solid
22
dBm so it seems like there is adaquate drive to the final device but
the
510 stage just won't deliver more than about 1-2 watts as above. It
is
as though the latter stage needs a few more dB of gain but it
already
seems to be straining to deliver quality (clean) reduced power. All
related comments/experiences are indeed appreciated, and I Thank You
in
advance.

Cordially, and 73,

Bob


[Non-text portions of this message have been removed]