Hi Ruud/Chris and rest of BITX group,

Talking about transistors in the TX chain: Finished most of the tx
chain of my bitx17 yesterday evening (at this moment still without pa
stage). I connected 2 meters of wire to the Q14 amp stage. With a
seperate rx i was able to receive a weak generated ssb signal (audio
modulated) on 18.1 MHz. When I measure behind Q14 with a field
strength measure device a get a very very small deflection; my
frequency counter (which is rather sensitive) did not respond with a
frequency value. Is this what can be expected or should RF levels be
higher just after Q14 ? I think the levels are too small and an
additional stage might be necessary. I have used a regular npn
transistor BC945 for my BITX17 since I had about 40 of them in the
junkbox. The e, b and c are stamped on the transistor housing which
made soldering easy. The receiver part seems to work fine with this
type of general purpose transistor as can be read in one of my
messages from last weekend.

73 de Ron
PA2RF



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

Hi Chris,

A second reaction on your remark about the 2N3866's in the driver-
stage.
I looked it up to be sure. You are right: the voltage gain and

power

gain are defined by the resistor values
(www.phonestack.com/farhan/bitx.html). The individual transistor
characteristics does not matter as long as the gain of the

transistor

is high enough for the frequency in use. Maybe this is the source

of

the difference between the BC337 and the 2N3866. The 2N3866 is a

VHF

power amplifier. The BC337 an audio transistor with medium current
and maybe is 14 MHz too much for it. I also saw that Farhan used

the

2N3866 also in the IF stage in his simple SSB tranceiver
(www.antentop.bel.ru). Three amplifier stages in the driver-stage

is

then enough. I had to use 4 of them to get enough gain for the

IRF510.

73

Ruud
PE2BS

- what you did not translate is a story about advised 2N3866. Is
that really related to the BITX project? As Farhan explained, the
values of the components defines the gain and not the

semiconductor

itself.
Have a nice weekend,
Chris.

开云体育

Julius

5.0 to 5.4 MHz might be a better choice for VFO frequency because it is much easier to build a stable VFO for 5 MHz than it is for 23 MHz.? Even applying a Huff & Puff stabiliser circuit for your VFO is easier at 5 MHz than it is at 23 MHz.

14.0 MHz - 9.0 MHz = 5 MHz
14.4 MHz - 9.0 MHz = 5.4 MHz

Arv K7HKL
_._

On Tue, 2005-03-08 at 19:43, Wijaya, Julius wrote:

hi chris,

i am bit confuse on how to measure this crystal filer (still learning :) ), i had this 9MHz Crystal filter with 2.3KHz filtering bandwidth,
lets say that this filter works fine, while i'm in a progress studying about radio, i calculate that if i want to make a 20m receiver, with 9MHz IF filter, receving range is about 14.0Mhz to 14.4Mhz, i need to have a vfo that tune from 23.0Mhz to 23.4Mhz.

is that correct?

it is hard to find a match crystal set here in my town to make a ladder filter, so i am thinking about using this FL-30 ssb filter.

rgds
julius

* REPLY SEPARATOR? *

On 3/8/2005 at 4:06 PM vdberghak wrote:

>Hi Julius,
>what is important for a filter is that the input and output
>impedance and capacitance is correct. A very good filter that is
>shunted the wrong way gives likely a poor filter shape. So you must
>do some investigation on those filters or just try them and measure
>with the sound card (and the program mentioned in 'links').
>Good luck,
>Chris.
>
>>
>> speaking about crystal filter, this receiver had several filters,
>FL-70, FL-30, etc, but those two filter is ssb filter, it was
>written on the component.
>>
>> i was thinking that could this filter replace the crystal filter
>on BITX20?
>>
>> please let me know ok...
>>
>> rgds
>> julius
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

Yahoo! Groups Sponsor

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• To visit your group on the web, go to:
  
  ?
• To unsubscribe from this group, send an email to:
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• Your use of Yahoo! Groups is subject to the .

?????????????????????????????????????????????????????????? .

hi chris,

i am bit confuse on how to measure this crystal filer (still learning :) ), i had this 9MHz Crystal filter with 2.3KHz filtering bandwidth,
lets say that this filter works fine, while i'm in a progress studying about radio, i calculate that if i want to make a 20m receiver, with 9MHz IF filter, receving range is about 14.0Mhz to 14.4Mhz, i need to have a vfo that tune from 23.0Mhz to 23.4Mhz.

is that correct?

it is hard to find a match crystal set here in my town to make a ladder filter, so i am thinking about using this FL-30 ssb filter.

rgds
julius

* REPLY SEPARATOR *

Hi Chris,

A second reaction on your remark about the 2N3866's in the driver-
stage.
I looked it up to be sure. You are right: the voltage gain and power
gain are defined by the resistor values
(www.phonestack.com/farhan/bitx.html). The individual transistor
characteristics does not matter as long as the gain of the transistor
is high enough for the frequency in use. Maybe this is the source of
the difference between the BC337 and the 2N3866. The 2N3866 is a VHF
power amplifier. The BC337 an audio transistor with medium current
and maybe is 14 MHz too much for it. I also saw that Farhan used the
2N3866 also in the IF stage in his simple SSB tranceiver
(www.antentop.bel.ru). Three amplifier stages in the driver-stage is
then enough. I had to use 4 of them to get enough gain for the IRF510.

73

Ruud
PE2BS

Hi Julius,
what is important for a filter is that the input and output
impedance and capacitance is correct. A very good filter that is
shunted the wrong way gives likely a poor filter shape. So you must
do some investigation on those filters or just try them and measure
with the sound card (and the program mentioned in 'links').
Good luck,
Chris.

speaking about crystal filter, this receiver had several filters,

FL-70, FL-30, etc, but those two filter is ssb filter, it was
written on the component.

i was thinking that could this filter replace the crystal filter

on BITX20?

please let me know ok...

rgds
julius

Please look at the shape of that filter.
As I understood, it will always be one peak. Not really suitable for
SSB I think.
Good luck,
Chris.

--- In BITX20@..., pe2bs@t... wrote:

Hi Arv,

Thanks for your message. I planned some experiments with the

filters and

the SpectrumAnalyzer when I finished the BITX20. The filter of

JF1OZL was

new for me. I will try that too.

73,
Ruud
PE2BS

-- Oorspronkelijk bericht --
To: BITX <bitx20@...>
From: Arv Evans <arvevans@e...>
Date: Sun, 06 Mar 2005 19:07:37 -0700
Subject: [BITX20] Crystal filters...
Reply-To: BITX20@...


FYI

I noticed that JF1OZL uses resistors instead of capacitors in his
crystal ladder filters.
See: <> for his diagrams.
This might be interesting for those of you that are having

problems

getting the filter
response that you want.

Arv
_._

Arv's Web Page
.


Bijlage: Radio_Signature.png

_____________________________________________________________________

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een domeinnaam bij Tiscali. Ga naar

hi,

i am just starting to built my own homebrew radio, actually, i found that this is enjoying, and a good hobby because usually i only work with electronics on audi amps, tv and stuff, not radio, in other words, i am new to this(radio).

long time ago i had this R71e icom receiver, it does not work anymore, so i took out everything inside it, without trying to fix it :(.

speaking about crystal filter, this receiver had several filters, FL-70, FL-30, etc, but those two filter is ssb filter, it was written on the component.

i was thinking that could this filter replace the crystal filter on BITX20?

please let me know ok...

rgds
julius

* REPLY SEPARATOR *

Hi Arv,

Thanks for your message. I planned some experiments with the filters and
the SpectrumAnalyzer when I finished the BITX20. The filter of JF1OZL was
new for me. I will try that too.

73,
Ruud
PE2BS

-- Oorspronkelijk bericht --
To: BITX <bitx20@...>
From: Arv Evans <arvevans@...>
Date: Sun, 06 Mar 2005 19:07:37 -0700
Subject: [BITX20] Crystal filters...
Reply-To: BITX20@...


FYI

I noticed that JF1OZL uses resistors instead of capacitors in his
crystal ladder filters.
See: <> for his diagrams.
This might be interesting for those of you that are having problems
getting the filter
response that you want.

Arv
_._

Arv's Web Page
.


Bijlage: Radio_Signature.png

_____________________________________________________________________

Je eigen persoonlijk e-mailadres bij Tiscali? Registreer nu
een domeinnaam bij Tiscali. Ga naar

开云体育

?

there are big diffrence for the Ci in both devices, IRF510 Ci=150pF and IRF520=600pF,
so that means it could not operate on higher freq.

thanks
julius

* REPLY SEPARATOR? *

On 3/7/2005 at 9:15 AM Paolo Cravero as2594 wrote:

>ubberalles@... wrote:
>
>Hi
>
>> i found IRF520 from an old 120mm tape drive, i check on the internet
>that is both almost had similar characteristics.
>>
>> could IRF520 replace IRF510?
>
>Check the difference of "Input capacitance" between both devices.
>
>The more Ci the less is the operating (switching) frequency for the
>device. I remember something one order of magnitude difference between
>510 and 530 (5hundredthirty).
>
>Paolo IK1ZYW
>
>
>
>Yahoo! Groups Links
>
>
>

---

Celebrate Yahoo!'s 10th Birthday!

there are big diffrence for the Ci in both devices, IRF510 Ci=150pF and IRF520=600pF,
so that means it could not operate on higher freq.

thanks
julius

* REPLY SEPARATOR *

ubberalles@... wrote:

Hi

i found IRF520 from an old 120mm tape drive, i check on the internet that is both almost had similar characteristics.
could IRF520 replace IRF510?

Check the difference of "Input capacitance" between both devices.

The more Ci the less is the operating (switching) frequency for the device. I remember something one order of magnitude difference between 510 and 530 (5hundredthirty).

Paolo IK1ZYW

i found IRF520 from an old 120mm tape drive, i check on the internet that is both almost had similar characteristics.

could IRF520 replace IRF510?

regards
julius

开云体育

FYI

I noticed that JF1OZL uses resistors instead of capacitors in his crystal ladder filters.
See: <> for his diagrams.
This might be interesting for those of you that are having problems getting the filter
response that you want.

Arv
_._

?????????????????????????????????????????????????????????? .

---

Celebrate Yahoo!'s 10th Birthday!

Hi,
About the x-tals, we have discussed it before.
As you know, I have the x-tal filter working on 4,9152 MHz and fixed
it by trial and error (many errors ;-) ).
A friend of me builded the same filter with same component values.
The result was very bad, almost no signal passed the filter and the
shape was bad. The main difference was that he used an other brand x-
tals and switched (by accident) one non selected x-tal (the one that
was intended for the BFO).
We tried many capacitors, variable C's and coils to get the shape
like mine (see files in Photos directorie BITX17) but nothing
helped. Then we changed the x-tals to the same brand as mine and we
had almost the same result. Still some strange things that showed
that the filters did not behave exactly the same but anyhow, it
worked.
Later, I tried to see what happens if I changed components
(specially leaving the center capacitor out), using the method using
the sound card, the shape became only worse.
In all schematics with ladderfilters you always see the center
capacitor value much higher, ofter twice the value of the others.
Practice showed that real life gives sometimes a different value ;-)

By the way, in a posting I asked for response on the filter curve of
the 10 MHz ladderfilter (to compare with mine), you were the only
one that gave response. It is so easy with the soundcard method...

We both will wait for more reactions,
best regards,
Chris.

Hallo Chris,

Thanks for your message.
- Yes I got the wrong pin from his schema but I should have known
better. I used the LM386 many times before.
- The crystals were selected form 10 new crystals from "Barend". With
the IRF510 and the 2N3866 and some R's and C's the few new parts of
the trcv. I selected them and calculated in Excell the C's the way
Farhan discribed on his site:

Kristal freq_1 freq_2 freq1-freq2
1 9998,78 9996,2 2,58
2 9,998,81 9,9963
3 9998,79 9996,4 2,39
4 9,998,85 9,9964
5 9,998,76 9,9963
6 9,998,82 9,9964
7 9,998,69 9,9962
8 9,998,87 9,9963
9 9998,78 9996,3 2,48
10 9998,78 9996,4 2,38

gem.shift 2,4575

C1= C3= 51,6075 pF
C2= 98,3 pF


The shape was as in the picturebox. After experiments and leaving
the 100pF the shape was better (see picturebox).
- What I understood is that the gain is defined by the components in
the bidirectional parts of the trcv. I used the 2N3866 in the driver
stage wich is not bidirectional. First I used the BC337 (I had lots
of them). They gave not enough gain to drive the IRF. Then I used the
2N3866 and I saw more signal on the scope but still not enough for 4
watt. I just included an extra amplifierstage. Now I have 4 to 5 watt
output.
- The BITX20-psk is allmost ready. I made the print in an old modem-
case. Pictures in the picture box. Now I have to make a good
antennatuner for it and an extra VXO for PSK.

73,

Ruud
PE2BS


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

Hi Ruud,
- the fault in the connections of the LM386 has been posted and is
also in the directory ''files'. I asked Farhan more then once to
correct the schematic but without result.
- for the best shape of the filter without C: the only explanation

I

can imagine is that the x-tals are not exactly the same. If you

maje

the same filter with other x-tals (or the same x-tals in different
order) I think you end up with other values.
- what you did not translate is a story about advised 2N3866. Is
that really related to the BITX project? As Farhan explained, the
values of the components defines the gain and not the semiconductor
itself.
Have a nice weekend,
Chris.

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

Hello BITX-ers,

Excuse for the email in Dutch. I though the message was going to

his

private email. The translating (short):
- It took me some time to make the BITX because I had problems

with

the LM386 (VCC on 5 instead of 6 damaged the IC).
- I spend some time making a good shape for the IF. I still do

not

understand the result (no C in the middle of the filter). Never

seen

that before in an IF-Xtalfilter.
- The Huff and Puff stabilizer worked fine in some of mine home-

made

receivers.

73,
Ruud
PE2BS

Hi Ruud,
- the fault in the connections of the LM386 has been posted and is
also in the directory ''files'. I asked Farhan more then once to
correct the schematic but without result.
- for the best shape of the filter without C: the only explanation I
can imagine is that the x-tals are not exactly the same. If you maje
the same filter with other x-tals (or the same x-tals in different
order) I think you end up with other values.
- what you did not translate is a story about advised 2N3866. Is
that really related to the BITX project? As Farhan explained, the
values of the components defines the gain and not the semiconductor
itself.
Have a nice weekend,
Chris.

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

Hello BITX-ers,

Excuse for the email in Dutch. I though the message was going to

his

private email. The translating (short):
- It took me some time to make the BITX because I had problems

with

the LM386 (VCC on 5 instead of 6 damaged the IC).
- I spend some time making a good shape for the IF. I still do not
understand the result (no C in the middle of the filter). Never

seen

that before in an IF-Xtalfilter.
- The Huff and Puff stabilizer worked fine in some of mine home-

made

receivers.

73,
Ruud
PE2BS

Hello BITX-ers,

Excuse for the email in Dutch. I though the message was going to his
private email. The translating (short):
- It took me some time to make the BITX because I had problems with
the LM386 (VCC on 5 instead of 6 damaged the IC).
- I spend some time making a good shape for the IF. I still do not
understand the result (no C in the middle of the filter). Never seen
that before in an IF-Xtalfilter.
- The Huff and Puff stabilizer worked fine in some of mine home-made
receivers.

73,
Ruud
PE2BS

Hi Ruud & fellow bitx-ers,

Dank voor je foto's en schema's. Dat is nog een flinke klus geweest!
I like your set-up of the rig with the up and bottom partition. Hope
you will be able to make your first (CW ?) QSO on short notice.
I have been working on my Huff and Puff driven BITX17 yesterday and
installed most of the 1 transistor amp circuits. Also finished the IF
part with 10 MHz X-tals. Hope to receive something coming weekend.

Lot's of homebrew fun and 73 from Zoetermeer,

Ron
PA2RF


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

Hi BITX-ers,

The BITX20-psk is working in CW (by computer) with 4 watt. Now I

have

to make an extra antenna and built a second VXO for the PSK

frequency.

Files with the schema (almost the same as Farhan's)in SPlan 5.0 are
uploaded in the files area. In the photobox I dropped the schema's

in

JPG and some pictures of the equipment.

73,

Ruud
PE2BS