80m hexfet power amplifier by W7ZOI
Hi All, Does anyone have built this little marvel? Any thoughts? I'm guessing the only mod(s) needed to move it to 40m is the LPF and maybe L1, am I right? Gonna get another 12V battery ASAP.  found it here: 73, Dan HK4DEI
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Used a combo of Drill press and punch with some files. I need to get a saw even a nice small metal hand saw. It was all a squeeze for sure AGC is going to be tough hihi
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I always drill 4 holes on the inside of the window lines and use a hand fret saw to cut the center out.
Then you need some elbow grease to make the hole neat.
Now if you can get a bezel for the display, then you are in business!
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At 07/07/2017, you wrote: Aperture all within display outline, so a file and a bit of judicious 'elbow-grease' would cure any uglies. All those extras! Well done!
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Aperture all within display outline, so a file and a bit of judicious 'elbow-grease' would cure any uglies. All those extras! Well done!
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Nice job getting all that stuff on the panel! I put the mic, phone and key jacks on the side of my box to save space on the front panel for future additions.
?I can't vouch for how good that particular one is, however. I have an . I've had it forever, They want $55 for it now. I know I didn't pay that much a hundred years ago when I bought one.
--
John - WA2FZW
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Re: VK and ZL group buy of Jack W8TEE VFO boards
Whoops! Sorry, that
wasn't intended for the group, just Martin.
Bill, VK7MX
On 7/07/2017 12:38 PM, Bill Maxwell
wrote:
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G'Day Martin
Jack W8TEE's VFO
boards arrived from the USA yesterday. I bought 15 boards
from him and have therefore divided my total costs to date
by 15, yielding a landed price per board of $12.30.
Went to the Post
Office this morning to check packaging costs and postage.
The boards are a touch bigger than I would be comfortable
about simply putting in a normal envelope, as I suspect they
may well punch through the ends of the envelope and might
actually escape. A normal envelope also offers little
protection to the pcb traces etc.
My preferred
package is the stiff cardboard AusPost disk or photo mailer,
at $1.30. Then there is actual postage of either 1 or 2
boards anywhere in Australia at? $2.00.
Total cost? for 2
boards posted to you would therefore be $27.90.
I can accept
payment by Paypal using the wrmaxwell@...
email address, or by direct deposit to BSB 814282, Account
10234433, W R Maxwell.
If paying by
Paypal please send the money as a gift, but being sure to
include your postal address in the "notes" section. I am
only seeking to recover my actual costs in this exercise, as
my contribution to supporting the BITX 40 project. I have
not factored any Paypal charges or commission into these
costings, so please don't use the "purchasing goods or
services" Paypal option, as that would put me out of pocket.
Of the 15 boards
received, I am keeping 2 for my use. I have reservations for
a further 9. Once I hear back from you and the others on the
list, I will advertidse whatever boards remain on the BITX
group.
73
Bill, VK7MX
On 12/06/2017 10:48 AM, martin Fraser
wrote:
Count me in on 2 please
Regards martin?
VK6FEEE
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Re: VK and ZL group buy of Jack W8TEE VFO boards
G'Day Martin
Jack W8TEE's VFO
boards arrived from the USA yesterday. I bought 15 boards from
him and have therefore divided my total costs to date by 15,
yielding a landed price per board of $12.30.
Went to the Post
Office this morning to check packaging costs and postage. The
boards are a touch bigger than I would be comfortable about
simply putting in a normal envelope, as I suspect they may
well punch through the ends of the envelope and might actually
escape. A normal envelope also offers little protection to the
pcb traces etc.
My preferred package
is the stiff cardboard AusPost disk or photo mailer, at $1.30.
Then there is actual postage of either 1 or 2 boards anywhere
in Australia at? $2.00.
Total cost? for 2
boards posted to you would therefore be $27.90.
I can accept payment
by Paypal using the wrmaxwell@... email address, or by
direct deposit to BSB 814282, Account 10234433, W R Maxwell.
If paying by Paypal
please send the money as a gift, but being sure to include
your postal address in the "notes" section. I am only seeking
to recover my actual costs in this exercise, as my
contribution to supporting the BITX 40 project. I have not
factored any Paypal charges or commission into these costings,
so please don't use the "purchasing goods or services" Paypal
option, as that would put me out of pocket.
Of the 15 boards
received, I am keeping 2 for my use. I have reservations for a
further 9. Once I hear back from you and the others on the
list, I will advertidse whatever boards remain on the BITX
group.
73
Bill, VK7MX
On 12/06/2017 10:48 AM, martin Fraser
wrote:
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Count me in on 2 please
Regards martin?
VK6FEEE
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It's done took a few days of mods and hole drilling still have to work on my LCD display cutting in .....as you can see not so good at it yet hihi.
In total it has an added Keyer, Nescaf Filter and zero beat, soon AGC once I either build one or get a few boards.
From left to right FS // CW FS // Nescaf Filter Center // Nescaf Filter Bandwidth // Nescaf On/Off // Vol // Head Phones // Mic.
Above the mic and phones is the zero beat and the led for it is the yellow one above left of the tune lower right of tune is nescaf led. The zero beat is not the built in one but a LED version based off a 567 tone detector, I have built a few and love them.
All in all it was a fun build and can't wait for some park ops.
73
?Happy Building
?
?David
?N8DAH
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Rather than concentrating on a number, I'd be testing at what is required for your area (largely dictated by ambient noise level).?
That is your rig should be very quiet with no antenna connected and the volume turned up (it should be free of whine or hash from the DDS VFO). ?
Connecting an antenna should lead to a significant increase in noise. If there is there's enough gain. If there isn't there's not enough gain. It's as simple as that.?
And any remaining synthesiser noise should be completely smothered by RF noise pick up.?
If you're really critical take your Bitx to a quiet location. ?There have been cases where I thought one had adequate sensitivity in my noisy home QTH but was plagued with synthesiser noise away from home.?
Repeat the antenna disconnect/connect test there. ?Then you'll truly find if the sensitivity is enough or not.?
Here's what one can sound like at such an RF quiet location.?https://www.youtube.com/watch?v=9n_QYo6yyd0
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Re: dipole antenna changes, big improvement
I raised it up yesterday.? It is fed with coax.
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?Low pass filter in BITX works best with 50 ohm input, otherwise sensitivity will suffer...
With long or short wire I always had to retouch my BPF...
On Jul 7, 2017 1:15 AM, "Sandeep Lohia" < sandeeplohia12@...> wrote: One need to retune ( 27 pf variable trimmer + one air wound LPF coil ) ?BPF if antenna is not 50 ohm, long wire is not 50 ohm... was talking about old 2.2uh inductors,?
Didn't tested 6 uh inductance BPF yet...
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One need to retune ( 27 pf variable trimmer + one air wound LPF coil ) ?BPF if antenna is not 50 ohm, long wire is not 50 ohm... was talking about old 2.2uh inductors,?
Didn't tested 6 uh inductance BPF yet...
On Jul 5, 2017 7:36 PM, "Larry Acklin" < acklin@...> wrote: YEP!? Had a QSO with a guy in Alabama, he was running 500W, I was running 5W. ?20M SSB.
Says a lot- my rig probably cost less than his microphone. ($65 for a Bitx20 V3SBL1 and a junked SSB CB for the crystal filter)
73 Larry KB3CUF
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Re: what distance have you logged
For SSB about 1980 miles to KL7CWN with 5w and 80 meter ocf dipole at about 25 feet. On wspr I logged AU at 9246 miles.?
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A very good site, kits, tings to build, and books to download.
Just a note on this file.? NOWHERE IN THE FILE is the name of the book mentioned!!!!? I hadda write to ARRL to find out the name of the book.? I bought the book.? Now, I have little time to read it! Joe W3TTT
Chapter ONE of Experimental Methods in RF Design (EMRFD) is available at:
--
73, Joe W3TTT
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Re: dipole antenna changes, big improvement
Did you have it up when I talked to you last week? That was the
first
time that I heard you since we started the group. I too have an
inverted vee up 50'
Ed W0OIC
On 7/5/2017 8:50 PM, KC8WBK via
Groups.Io wrote:
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I added a support
line to the middle of my dipole and went from a sagging dipole at
35 feet to an inverted vee at 50 feet.? This is a big improvement,
because I rarely heard stations out west before, and I just had a
long conversation with a operator in Nevada.? Wow, now I want to
put it up even higher.
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BITX QSO Night, Sunday, July 9, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
BITX QSO Night, Sunday, July 9, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!
To participate, call CQ BITX at 7pm sharp, your local time, on Sunday. Call off and on for about 15 minutes. It is helpful if you call CQ BITX with your name and location.? Repeat your call a number of times if conditions are weak.
This is a worldwide event at 7pm in each time zone.? You may participate in any time zone, regardless of your location, so you may wish to call in at 6pm, 7pm and 8pm, your local time, to contact hams in adjacent time zones.
The backup frequency in case of QSB or other noise is 7210 kHz.
Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.
This is an undirected, scheduled event.? The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls at 7pm on Sunday.? Talk to you then!
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To beat this poor old dead horse a little more. ?Back in the 80s Borland got it right with Turbo Pascal. ?Back then Microsoft was charging something like $500 for a compiler and copy protection wasn't like it is today. ?Borland introduced Turbo Pascal for
something like $49 or $99 with manuals, etc. ?In other words it was so cheap that you would buy it to get the manuals, etc. ?Even though you could get a pirated copy there was enough value added such that pirating was a trickle and Borland could ignore it.
?It is a similar model for Fedora and RedHat. ?If you want the free version, download Fedora and?have at it. ?But if you want support, etc buy RedHat.
As for books, it is a bit more tricky. ?In my case, here in geezerville, I much prefer a nice book that I can mark in, etc, so, that is enough value add for me. ?I'm pretty sure I am in the minority. ?I know there are some value adds that come with books
such as DVDs and I guess that helps a bit. ?But, I think the solution is a price point and clever value add such that for, say 80% of the market, the real thing is worth it.
And, by the way, Jack's book is way?worth it.
73,
Pat AA4PG
Pat Griffin
http://www.cahabatechnology.com/aa4pg.html
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I appreciate your comments, Andrew, especially since there are literally hundreds of sites where my books are being given away free. My daughter works
at a major publishing house and they have three people on staff whose only job is to find such sites and have the legal department issue cease and desist orders. It's like trying to divert Niagara Falls with a bucket.?
I enjoy writing. If I didn't, I would have stopped years ago because, financially, it's no longer worth it. And therein is the problem. Good authors who
depend on writing income can no longer afford to write. Books that would have brought knowledge, pleasure, and joy to thousands simply won't be written. ?If a new author gets lucky and gets a book published and it is successful, it is quickly copied and neither
the author who did the work nor the publisher who took the risk, are rewarded. It doesn't take an economist to figure where that goes.
Clearly, it is tempting to download a book that you want and not have to pay for it. As I stand here with my bucket, I know there's nothing I can do to
stop those people who make our property available for download. Given that, my position is: If you take my book and read it and feel that you have benefited from it, then go out and buy a copy. It's as close to a win/win as we're going to get. You get the
read the book risk free and, if I've done a good job for you, you end up paying me in the end. I also feel that those who do that actually feel better having paid for the book.
Telling you not to download a free book probably isn't going to sway anyone. However, if it turns out to help you, you should help that person in return.
Jack, W8TEE
From: Andrew Krause <andrew.krause@...>
To: [email protected]
Sent: Tuesday, July 4, 2017 5:15 PM
Subject: Re: [BITX20] A Good Book
I just want to say that I have a hard time with people posting PDF links to in-print material that is copyrighted. Someone worked very hard to create a text to educate others. They're entitled to profit from that.
Furthermore, this knowledge has value, and is worth paying for.?
It appears that this single chapter is made freely available, so no foul here. But the other day someone posted an entire scanned PDF of a book. What are the groups rules on this??
On Tue, Jul 4, 2017 at 4:50 PM Ken KM4NFQ < km4nfq@...> wrote:
Chapter ONE of Experimental Methods in RF Design (EMRFD) is available at:
More on the first transmitter here:
and more stuff related to EMRFD here:
The latest iteration of EMRFD is the Classic Edition.
A CD-ROM is included with two additional Classic Editions
(scans of printed books in PDF format) written by Wes Hayward, W7ZOI.
Solid State Design for the Radio Amateur (1986)
Introduction to Radio Frequency Design (1994)
SSDRA is the precursor of EMRFD.
IRFD is Maths intensive.
Regards,
Ken, KM4NFQ
--
Andrew Krause
General Class Amateur Radio License: KM4ZJO
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Let's take the subject of Arduino Programming.
There are literally dozens of published books about that subject. If you look at the Table of Contents, they all cover the same thing. How many do you need to buy to get started with Arduino Programming?
That is why I recommend using your local PUBLIC LIBRARY to find books. If your local PUBLIC LIBRARY doesn't have the book in its collection, then inquire about the INTERLIBRAY LOAN SERVICE. Your local librarian will be happy to help you use the service.
One way to find books in a library is to search World Cat. One feature of World Cat is that they will list libraries that have the book. For example, look for Experimental Methods in RF Design at World Cat. You will get a page of search results. Clicking on the top search item you are taken to the book's page. Scrolling down, there is a box labeled: Enter your location:Type in your ZIP code and libraries close to that will be displayed. This is an excellent way to find out-of-print books. My local library will allow me to check out a book for 21 days. I can renew the book up to four times, if there are no holds on it. The INTERLIBRARY LOAN service can obtain books from out--of-state if there are no copies of the book in-state. It is very rare that the library cannot find and loan a book to me.
PUBLIC LIBRARIES are NOT against the law.They are probably one of the BEST ways your taxes are used. It is a great way to find a book about Arduino Programming without buying a dozen books that all cover the exact same stuff. Often books go out-of-print, and the Publisher will not reprint it. The PUBLIC LIBRARY is a great way to find and borrow such a book. I encourage everyone to use their local PUBLIC LIBRARY. If you don't have a library card, get one at your local branch library. Here is a recent experience I had using my local PUBLIC LIBRARY.
There is a book called The Electronics of Radio by Rutledge.
It uses the Norcal40A as the radio for experimentation.
I decided I wanted to take a look at it.
It starts out at $35+ USD for a used copy. (See: )
So I used the PUBLIC LIBRARY's INTERLIBRARY LOAN SERVICE.
The book arrived in a couple of weeks from a University Library.
It was evident to me right off the bat that the content of the book
was way over my head. I sure am glad I didn't spend $35 to find that out.
When I do find a book at my local public library that clicks with me,
then I usually try to find a used copy of the book,using
if I want a copy on my own bookshelf. But I can say from experience
that not ALL the books on any given subject are good books. Sometimes
they just don't resonate with me. I do not buy copies of those books.
Summary: Use your local PUBLIC LIBRARY !!!
Even small towns usually have a branch library.
And the INTERLIBRARY LOAN SERVICE makes any branch, large.
Regards, Ken, KM4NFQ
On Thu, Jul 6, 2017 at 9:12 AM, Peter Parker <parkerp@...> wrote: Another one I recommend (though more for the theory than practical side) is Ron Bertrand's Radio Theory Handbook.?
This takes you from basic to advanced, going a bit higher than our exam requirements.?
A review I did is at?
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Re: BITX40 Microphone options
I use the supplied mic insert on a old ?pen ?works we'll I use PTT on the radio?
On 6 Jul 2017 15:25, "Raj vu2zap" < rajendrakumargg@...> wrote: What Bitx40 needs is an extra amp stage for the mic.
With my lung capacity down I can't do "haaaaloo" level of yelling anymore so I am using an amped motorola mic.
If you are adventurous try a preamp for the mic with mods and a mic drive control for better control.
An opamp with gain control is better suited for the bitx40. If you don't want to disturb the Bitx40 board then
use a capacitor to couple a preamp.
Raj
At 06/07/2017, you wrote:
>If compactness is essential you could use the supplied element and put it in case with the end-cap for the BNC antenna connector (also supplied). As it happens the microphone element fits snugly in. You can pierce two holes in the plastic and use a small press switch (might even have been supplied with the Bitx) for the PTT.
>
>Described in this video:
>
>
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Re: BITX QSO Night, Sunday, July 16, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Sorry, posted with the wrong date!? This Sunday, July 9 and every Sunday is BITX QSO night.
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N8DAH
Raj vu2zap
ekelley
