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---

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Dear Ron,
splended idea to make it for 17 mtrs.
In your message you asked for suggestions, you want to have more
suggestions then all the postings in this newsgroup, including
Photos, Files etc?
Can you be more precisely what else you need?
By the way, you can show your progress in this newsgroup, you do not
need an other website for it.
Best regards,
Chris.

Dear bitx20 homebrewers,
I intend to build the BITX for the 17m WARC band (18.068-18.168

MHz). My ultimate goal will be to work psk31 with this splendid rig.
Has anyone suggestions to convert bitx20 to bitx17. VFO must be
changed of course and RF filters... I intend to keep my progress
updated on my website (see below).

73 de Ron
PA2RF
pa2rf@y...





---------------------------------
Do you Yahoo!?
Yahoo! Search presents - Jib Jab's 'Second Term'

Thanks for advice dear Chris,
Saw on the forum that the BITX17 already seems to exist!
OK, past couple of days I started to setup the power supply unit
capable of delivering the required voltages.
Also did some trials with a VFO working from 8.060 - 8.180 MHz. (+ 10
MHz IF will give the proper range) Frequency range seems to be ok but
stability is bad. After 20 minutes waiting freq shift of 1 KHz still
exists. I think I will order some components for a HuffAndPuff
circuit for stabilizing purposes.
Or maybe a FET Hartley oscillator. We'll see.
Bye for now and till next time.
Dank voor je reactie Chris. Leuk om te zien dat andere om druk met de
bitx in de weer zijn.
73 de Ron
pa2rf


--- In BITX20@..., "vdberghak" <vdberghak@z...> wrote:

Dear Ron,
splended idea to make it for 17 mtrs.
In your message you asked for suggestions, you want to have more
suggestions then all the postings in this newsgroup, including
Photos, Files etc?
Can you be more precisely what else you need?
By the way, you can show your progress in this newsgroup, you do

not

need an other website for it.
Best regards,
Chris.

Dear bitx20 homebrewers,
I intend to build the BITX for the 17m WARC band (18.068-18.168

MHz). My ultimate goal will be to work psk31 with this splendid

rig.

Has anyone suggestions to convert bitx20 to bitx17. VFO must be
changed of course and RF filters... I intend to keep my progress
updated on my website (see below).

73 de Ron
PA2RF
pa2rf@y...





---------------------------------
Do you Yahoo!?
Yahoo! Search presents - Jib Jab's 'Second Term'

the 1 Khz drift is more of a construction problem that a design problem.
I would suggest that you try the following:
1. make all the components connect to each other with short leads and without any 'jiggly' wires.
2. put an epoxy glue over the coil and stick the coil to the board with a drop of expoy.
3. put a sheild around the vfo (i know it is too much work).
4. Are u connecting to the tuning capacitor with flexible wire? use a short stiff copper wire or a resistor tail end.The ground end should be directly in contact with the chassis.
5. Make sure that your regulator is actually regulating. Check the diode (i have often mistakend 1N4148s for other zeners).

Unfortunately, an open VFO on a work-bench is rarely stable. Especially, if your coil has an low permeability like the tap washers.

- farhan

What is your opinion about working with digimodes (like rtty and psk31) with the bitx, Ashhar? Is there any experience in this field ? A 10 Hz stability requirement for psk31 is very though!! (altough i managed to get an old kenwood ts515 with tubes working on psk31..)

Ron

pa2rf

the 1 Khz drift is more of a construction problem that a design problem.
I would suggest that you try the following:
1. make all the components connect to each other with short leads and
without any 'jiggly' wires.
2. put an epoxy glue over the coil and stick the coil to the board with a
drop of expoy.
3. put a sheild around the vfo (i know it is too much work).
4. Are u connecting to the tuning capacitor with flexible wire? use a
short stiff copper wire or a resistor tail end.The ground end should be
directly in contact with the chassis.
5. Make sure that your regulator is actually regulating. Check the diode
(i have often mistakend 1N4148s for other zeners).

Unfortunately, an open VFO on a work-bench is rarely stable. Especially,
if your coil has an low permeability like the tap washers.

- farhan

On Thu, 3 Feb 2005, pa2rf wrote:

>
>
> Thanks for advice dear Chris,
> Saw on the forum that the BITX17 already? seems to exist!
> OK, past couple of days I started to setup the power supply unit
> capable of delivering the required voltages.
> Also did some trials with a VFO working from 8.060 - 8.180 MHz. (+ 10
> MHz IF will give the proper range) Frequency range seems to be ok but
> stability is bad. After 20 minutes waiting freq shift of 1 KHz still
> exists. I think I will order some components for a HuffAndPuff
> circuit for stabilizing purposes.
> Or maybe a FET Hartley oscillator. We'll see.
> Bye for now and till next time.
> Dank voor je reactie Chris. Leuk om te zien dat andere om druk met de
> bitx in de weer zijn.
> 73 de Ron
> pa2rf
>
>
> --- In BITX20@..., "vdberghak" wrote:
>>
>> Dear Ron,
>> splended idea to make it for 17 mtrs.
>> In your message you asked for suggestions, you want to have more
>> suggestions then all the postings in this newsgroup, including
>> Photos, Files etc?
>> Can you be more precisely what else you need?
>> By the way, you can show your progress in this newsgroup, you do
> not
>> need an other website for it.
>> Best regards,
>> Chris.
>>
>>> Dear bitx20 homebrewers,
>>> I intend to build the BITX for the 17m WARC band (18.068-18.168
>> MHz). My ultimate goal will be to work psk31 with this splendid
> rig.
>> Has anyone suggestions to convert bitx20 to bitx17. VFO must be
>> changed of course and RF filters... I intend to keep my progress
>> updated on my website (see below).
>>> 73 de Ron
>>> PA2RF
>>> pa2rf@y...
>>>
>>>
>>>
>>>
>>>
>>> ---------------------------------
>>> Do you Yahoo!?
>>>? Yahoo! Search presents - Jib Jab's 'Second Term'
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>

---

Do you Yahoo!?
Yahoo! Search presents -

Hi Ron,

Although al bit late I may have some suggestions for PSK. I also
build a BITX20 for PSK. Last weekend I completed the interface from
the TRCV to the soundcard. The schema is uploaded as a PDF file in
the file-box.

Some remarks:
- To avoid "earthloops" effects I used two tr's 1:1 from an old
computerswitchingsupply. I also used an optocopler from the same
supply. You can recognize the optcoplers by the DIL6 package. (pin 1
Anode D, pin 2 Cathode D, pin 3 NC, pin 4 Emitter T, pin 5 Collector
T, pin 6 Base T).
- You can easily check for low frequency sounds (earthloop and
others, special lower than 500 Hz!!) by using the waterfalldiagram in
HamScope. No lines no sound. To avoid every possibility I used 3u3
capacitors between the stages of LF. The low frequency's below 500Hz
are almost blocked. (See picture HamScope in picture box).
- The signal send to the computer by Line in comes back by Line out.
To my suprise came peaks of the signal through T6 and T5 to T4.
Oscillation was the result. T3 was added as a switch.
- When I used SpectrumAnalyzer I saw a peak in the signal I first
could not explain (see picture in the picture box). After a while I
discovered that the output impedance of the LM386 did not match with
Tr2. First I added a variable resistance. The value had great affect
on the frequency spectrum! Check with SpectrumAnalyzer. R18=33 ohm
was the best in my situation.
- The oscilator in my BITX20 will (if possible) be a VXO on 24MHz.
The reason for this is simple: lots of cristals in the junkbox and a
good supression of the signal by the Pi-filter. I can vary tot 5 kHz
when I use three crystals. But the frequency of the oscilator also
goes about 5 Kc up when a crystal is added!
The VXO is not ready yet. I still have to work for enough output for
the balance mixer.
With CWGet it is possible to decode CW in the first part of the band.
When everything is working well iI wil order a special crystal for
PSK.

73,

Ruud
PE2BS


--- In BITX20@..., Ron Brink <pa2rf@y...> wrote:

Dear bitx20 homebrewers,
I intend to build the BITX for the 17m WARC band (18.068-18.168

MHz). My ultimate goal will be to work psk31 with this splendid rig.
Has anyone suggestions to convert bitx20 to bitx17. VFO must be
changed of course and RF filters... I intend to keep my progress
updated on my website (see below).

73 de Ron
PA2RF
pa2rf@y...





---------------------------------
Do you Yahoo!?
Yahoo! Search presents - Jib Jab's 'Second Term'

Hi Ruud,

First of all; hartelijk dank voor alle info, leuk om ham uit PA-land
hier te ontmoeten!
I really appreciate the good information you provided. Had a quick
look at your interface drawings which look very profi. I am in the
early stage of building the rig. I choose for the 18MHz WARC band
because I do not have equipment for this part of the spectrum yet and
i do not know what to expect (which is exciting). I finished PSU, LF
amp, (mechanics and part of electronics) for VFO which I think is not
stable enough yet (shortterm drift of 300Hz); so next step is to
include the huffandpuff circuit ("bijsloffer") from om pa0ksb in
order to obtain a drift less than 10 Hz (optimistic??). I started
with this module yesterday; found a nice 32MHz local oscillator on an
old PC board for reference oscillator which works fine. Rest of
hufenpuf components to be shipped in next week.
OK about PSK... I have very nice experience with MixW2.1 with
digimodes (rtty, psk31) and cwget and cwtype running on an old
Celeron 266 MHz pc ;i coupled this pc to a Kenwood TS515 from 1972
with tubes and made lots of qso's past year (on 80-40-20-15m) and cw
qso on a homebrew 30m xtal trscvr. I will keep all your good advice
in mind when i will be working on the interface, but first things
first. I am surprised you are using the vxo on 24 MHz. Did you
already make a qso with your bitx? Or are you still in the building
phase?
Bye for now and till next time,
Ron
PA2RF


--- In BITX20@..., "Ruud Jongeling" <pe2bs@t...> wrote:

Hi Ron,

Although al bit late I may have some suggestions for PSK. I also
build a BITX20 for PSK. Last weekend I completed the interface from
the TRCV to the soundcard. The schema is uploaded as a PDF file in
the file-box.

Some remarks:
- To avoid "earthloops" effects I used two tr's 1:1 from an old
computerswitchingsupply. I also used an optocopler from the same
supply. You can recognize the optcoplers by the DIL6 package. (pin

1

Anode D, pin 2 Cathode D, pin 3 NC, pin 4 Emitter T, pin 5

Collector

T, pin 6 Base T).
- You can easily check for low frequency sounds (earthloop and
others, special lower than 500 Hz!!) by using the waterfalldiagram

in

HamScope. No lines no sound. To avoid every possibility I used 3u3
capacitors between the stages of LF. The low frequency's below

500Hz

are almost blocked. (See picture HamScope in picture box).
- The signal send to the computer by Line in comes back by Line

out.

To my suprise came peaks of the signal through T6 and T5 to T4.
Oscillation was the result. T3 was added as a switch.
- When I used SpectrumAnalyzer I saw a peak in the signal I first
could not explain (see picture in the picture box). After a while I
discovered that the output impedance of the LM386 did not match

with

Tr2. First I added a variable resistance. The value had great

affect

on the frequency spectrum! Check with SpectrumAnalyzer. R18=33 ohm
was the best in my situation.
- The oscilator in my BITX20 will (if possible) be a VXO on 24MHz.
The reason for this is simple: lots of cristals in the junkbox and

a

good supression of the signal by the Pi-filter. I can vary tot 5

kHz

when I use three crystals. But the frequency of the oscilator also
goes about 5 Kc up when a crystal is added!
The VXO is not ready yet. I still have to work for enough output

for

the balance mixer.
With CWGet it is possible to decode CW in the first part of the

band.

When everything is working well iI wil order a special crystal for
PSK.

73,

Ruud
PE2BS


--- In BITX20@..., Ron Brink <pa2rf@y...> wrote:

Dear bitx20 homebrewers,
I intend to build the BITX for the 17m WARC band (18.068-18.168

MHz). My ultimate goal will be to work psk31 with this splendid

rig.

Has anyone suggestions to convert bitx20 to bitx17. VFO must be
changed of course and RF filters... I intend to keep my progress
updated on my website (see below).

73 de Ron
PA2RF
pa2rf@y...





---------------------------------
Do you Yahoo!?
Yahoo! Search presents - Jib Jab's 'Second Term'

Hi Ruud,
there is something wrong with your VXO. With a 13 MHz VXO that I and
an other ham use, a frequency shift of about 60 kHz can be reached!
I think you can only shift so less because you do have the VXO
directly on 24 MHz. Because that is an overtone x-tal, it will not
work as a VXO. What you can do is make the VXO with that x-tal on 8
MHz, then tripling it. Likely you will have then more then hundred
KHz shift possibility.
Good luck,
Chris.

- The oscilator in my BITX20 will (if possible) be a VXO on 24MHz.
The reason for this is simple: lots of cristals in the junkbox and

a

good supression of the signal by the Pi-filter. I can vary tot 5

kHz

when I use three crystals. But the frequency of the oscilator also
goes about 5 Kc up when a crystal is added!
The VXO is not ready yet. I still have to work for enough output

for

the balance mixer.

Hi Chris,

Thanks for your info. I guess you're right about the overtone
crystal. I am gonna try 8Mhz and triple it.
73
Ruud.


--- In BITX20@..., "vdberghak" <vdberghak@z...> wrote:

Hi Ruud,
there is something wrong with your VXO. With a 13 MHz VXO that I

and

an other ham use, a frequency shift of about 60 kHz can be reached!
I think you can only shift so less because you do have the VXO
directly on 24 MHz. Because that is an overtone x-tal, it will not
work as a VXO. What you can do is make the VXO with that x-tal on 8
MHz, then tripling it. Likely you will have then more then hundred
KHz shift possibility.
Good luck,
Chris.

- The oscilator in my BITX20 will (if possible) be a VXO on

24MHz.

The reason for this is simple: lots of cristals in the junkbox

and

a

good supression of the signal by the Pi-filter. I can vary tot 5

kHz

when I use three crystals. But the frequency of the oscilator

also

goes about 5 Kc up when a crystal is added!
The VXO is not ready yet. I still have to work for enough output

for

the balance mixer.

Hi Chris,

- The schema of the "VXO" I use for 24MHz is in the photobox. As you
can see I didn't use an inductive in serie with the crystals. The
shift is 4 KHz. That is enough for the PSK frequency. For CW I want
more shift. Can you give me some advice about the inductive?

- You were right about the impedance and shape of the filter changing
when I put the crystalfilter in the RX. I made a new shape picture
with the noise source on the antenna and the filter in the RX. The
best shape I got was with 100 pF on both ends but still 0 pF in the
middle of the filter. (See schema and screen picture in the picture
box). I do not understand this.

73,

Ruud
PE2BS

--- In BITX20@..., "vdberghak" <vdberghak@z...> wrote:

Hi Ruud,
there is something wrong with your VXO. With a 13 MHz VXO that I

and

an other ham use, a frequency shift of about 60 kHz can be reached!
I think you can only shift so less because you do have the VXO
directly on 24 MHz. Because that is an overtone x-tal, it will not
work as a VXO. What you can do is make the VXO with that x-tal on 8
MHz, then tripling it. Likely you will have then more then hundred
KHz shift possibility.
Good luck,
Chris.

- The oscilator in my BITX20 will (if possible) be a VXO on

24MHz.

The reason for this is simple: lots of cristals in the junkbox

and

a

good supression of the signal by the Pi-filter. I can vary tot 5

kHz

when I use three crystals. But the frequency of the oscilator

also

goes about 5 Kc up when a crystal is added!
The VXO is not ready yet. I still have to work for enough output

for

the balance mixer.