Arjan,
I do not understand what you ask. You may try it in the Dutch language.
Ik begrijp dat je vraagt of het normaal is dat er veel ruis uit de
ontvanger komt. Aan je vraagstelling maak ik op dat je dit niet normaal
vindt. Waarom zou dat niet normaal zijn? Als je aan de volume potmeter
draait, varieert dan ook het volume? Neem anders deel voor deel los om
vast te stellen waar de ruis ontstaat. Met vriendelijke groet,
Chris.

I have a question I the reception rx working of my BITX20 only I
well many noise on my audio this normal? can someone help me?
greeting Arjan pe1abe

Thanks for your helpful coments, Rahul.

You are right in the DDS issue, the PLL chip could be dificult to
find. I don't like DDS for the noisy output, but I am not tested
this and I am not make a DDS prototipe yet.

Using a PIC could be complicate in software programing and chip
programing, but then it is easy. Using a PIC offers more
posibilities to the transceiver and ease operation in my opinion.

I don't want to change the easy bilateral BITX configuration, I try
some high Ft transistor an then possibly I keep the low FI. I change
it to 12MHz for a problem with 10MHz in my BITX 15meter band. The
second armonic in 20MHz was at the antena with the useful signal at
21.185MHz, then ROE adjust was impossible !!!

Manuel
EB7HPM/EC7ALV


--- In BITX20@..., Rahul Srivastava <vu3wjm@y...> wrote:

Hi! Manuel,

It is not that we missed your work in fact we looked at it with

great interest. I was interested in a PLL design for VFO for long.
My opinion by using a PIC we complicate things.

Now a PIC and 145170 combo is as simple / complex as PIC and

AD9851. Since we can get the DDS chips as free samples hence a DDS
design appears more practical.

This does not means that a PLL is no viable , I have been working

on a dicreet design using 74192 chips with 10Khz ref pulling. The
same comcept can be implemented upon a MC145151 as done in Multipig
design.

You are right about high ft IF limitations . As per simulations

done by our Prof Rob there appers roll off of frequency due to
highly negative feedback nature of amp designs. I am evaluvating
results of high Ft BJT devices. Maybe one back this design would
evolve into a basic building block towards a multibander.

73

Rahul VU3WJM



eb7hpm <msraya@t...> wrote:

I want to contribute the comunity with my work and that you not
missed the earlier post. I don't want recognition, I only want to
ear coments about the circuit from more experienced hams, I am
computer engineer!! ;-). I was looking for a good, simple and easy
design in the Internet but I not found it, It is the reason I make
the design and program to drive the PLL.

I don't know the designs of VK6BRO Richard Hosking, but i think

they

are complex. I will publish this work in the huff-puff group.

P.D: My BITX with a FI of 32MHz and VCO of 53MHz is working, but

it

is very bad, with BF495 transistor, i only output 1 Wat, and the

PLL

show some inestability. The VCO, BFO and filter works at 32MHz. I
think the bilateral amplifier don't work at 32MHz. I miss

something?

73s
Manuel
EB7HPM/EC7ALV





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




---------------------------------
How much free photo storage do you get? Store your holiday snaps

for FREE with Yahoo! Photos. Get Yahoo! Photos

Try to change transistors.2sc2571a or bfr96 bfr91 or any other with
ft of 5 ghz.

There is big chance that capacitor values in crystal filter are not
appropriate. Even behavior of the crystals in lattice filter on such
high if should be considered.

It is not that we missed your work in fact we looked at it with

great interest. I was interested in a PLL design for VFO for long.
My opinion by using a PIC we complicate things.

Now a PIC and 145170 combo is as simple / complex as PIC and

AD9851. Since we can get the DDS chips as free samples hence a DDS
design appears more practical.

This does not means that a PLL is no viable , I have been working

on a dicreet design using 74192 chips with 10Khz ref pulling. The
same comcept can be implemented upon a MC145151 as done in Multipig
design.

You are right about high ft IF limitations . As per simulations

done by our Prof Rob there appers roll off of frequency due to
highly negative feedback nature of amp designs. I am evaluvating
results of high Ft BJT devices. Maybe one back this design would
evolve into a basic building block towards a multibander.

73

Rahul VU3WJM



eb7hpm <msraya@t...> wrote:

I want to contribute the comunity with my work and that you not
missed the earlier post. I don't want recognition, I only want to
ear coments about the circuit from more experienced hams, I am
computer engineer!! ;-). I was looking for a good, simple and easy
design in the Internet but I not found it, It is the reason I make
the design and program to drive the PLL.

I don't know the designs of VK6BRO Richard Hosking, but i think

they

are complex. I will publish this work in the huff-puff group.

P.D: My BITX with a FI of 32MHz and VCO of 53MHz is working, but

it

is very bad, with BF495 transistor, i only output 1 Wat, and the

PLL

show some inestability. The VCO, BFO and filter works at 32MHz. I
think the bilateral amplifier don't work at 32MHz. I miss

something?

73s
Manuel
EB7HPM/EC7ALV





---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of

Service.

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




---------------------------------
How much free photo storage do you get? Store your holiday snaps

for FREE with Yahoo! Photos. Get Yahoo! Photos

I want to contribute the comunity with my work and that you not
missed the earlier post. I don't want recognition, I only want to
ear coments about the circuit from more experienced hams, I am
computer engineer!! ;-). I was looking for a good, simple and easy
design in the Internet but I not found it, It is the reason I make
the design and program to drive the PLL.

I don't know the designs of VK6BRO Richard Hosking, but i think they
are complex. I will publish this work in the huff-puff group.

P.D: My BITX with a FI of 32MHz and VCO of 53MHz is working, but it
is very bad, with BF495 transistor, i only output 1 Wat, and the PLL
show some inestability. The VCO, BFO and filter works at 32MHz. I
think the bilateral amplifier don't work at 32MHz. I miss something?

73s
Manuel
EB7HPM/EC7ALV

---

How much free photo storage do you get? Store your holiday snaps for FREE with Yahoo! Photos.

???????? Chamfering the edges with a bit of emery or sand paper will also work.

73 Raj

At 08/07/05, you wrote:
>a bit of insulation tape on the core will certainly help matters.....
>\
>
>mm ali
>vu2ali
>
>
>
>Quoting Ashhar Farhan :
>
> >
> >
> >
> >
> >
> >
> > the problem with balun is that it has a sharp edges. these edges nick the
> >
> > enamelled wire being passed around. and the wire gets scrapped and touches
> >
> > the core. if more than two wires get nicked, they short, showing high
> >
> > resistance like you said.
> >
> >
> >
> > you need to be careful in not pulling the wire too tighly around the
> >
> > edges of the balun. a better way might be to coat the corners with a bit
> >
> > of paint.
> >
> >
> >
> > - farhan
> >
> >
> >
> > On Thu, 7 Jul 2005, g0fuw wrote:
> >
> >
> >
> > > Guys
> >
> > > I am building a BITX and have the rx working very nice.
> >
> > > However, there is a problem of microphics around the detector/af amp.
> >
> > > Ceramics replaced, as per past postings. No change.
> >
> > > I have now traced this to the balun core and find I have a 'short' of
> >
> > > about 60k between one of the windings and the core.
> >
> > > I have tried different wire and smoothing the holes before winding but
> >
> > > every time I get a 'short'.
> >
> > > I have tried a toroid core and that works without the problem.
> >
> > > Interested to know if anyone else has experienced this and if they
> >
> > > found a fix!
> >
> > > 73, Steve, G0FUW
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> > > Yahoo! Groups Links
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >?? YAHOO! GROUPS LINKS
> >
> >
> >
> >
> >??? Visit your group "BITX20" on the web.
> >
> >??? To unsubscribe from this group, send an email to:
> >? BITX20-unsubscribe@...
> >
> >??? Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>
>

--
Raj, vu2zap
Bangalore, South India.

---

NEW - crystal clear PC to PC

Chamfering the edges with a bit of emery or sand paper will also work.

73 Raj

--
Raj, vu2zap
Bangalore, South India.

I want to contribute the comunity with my work and that you not
missed the earlier post. I don't want recognition, I only want to
ear coments about the circuit from more experienced hams, I am
computer engineer!! ;-). I was looking for a good, simple and easy
design in the Internet but I not found it, It is the reason I make
the design and program to drive the PLL.

I don't know the designs of VK6BRO Richard Hosking, but i think they
are complex. I will publish this work in the huff-puff group.

P.D: My BITX with a FI of 32MHz and VCO of 53MHz is working, but it
is very bad, with BF495 transistor, i only output 1 Wat, and the PLL
show some inestability. The VCO, BFO and filter works at 32MHz. I
think the bilateral amplifier don't work at 32MHz. I miss something?

73s
Manuel
EB7HPM/EC7ALV

开云体育

Hi Paolo,
also in the (no longer exsisting) 'RAM' (Radio Amateur Magazine) was
the circuit discribed. That author is subcribed to the list (its me ;-)
No exact component details were given, only the principle, that the
schematic changes depending on needs and the link to the group.
The picture and short description is still on

Best regards,
Chris.

wrote:
Hi,
I just discovered that a series of 4 articles about BITX20 has been
published on the Italian magazine "RadioKit Elettronica" (03/2005 to

I wonder: is the author subscribed to this list?!?!?!?

73,
Paolo IK1ZYW

/

Hi Manuel,
perhaps, it is because that topic should be in the huff and puff yahoo
group?
Chris.

hi and greeting from UK.

I must have missed an earlier post on this .... All developments of the unit
I am watching but at the moment other club matters have slowed my progress
..it happens when you take on the HON SEC. post of a club ...

I will look at the files soon and thank you for placing them in the project.

Charles G4VSZ

Sorry, but realy nobody is interested in my PLL project??
It is MC145170 and 16F628 based. It is working 100% in BITX.
I post the schematic, photos and the C source code of working beta in
the files section.

Any coments?
Perhaps, my bad english is the problem?

Greetings
Manuel
EB7HPM/EC7ALV

Hi,
I just discovered that a series of 4 articles about BITX20 has been published on the Italian magazine "RadioKit Elettronica" (03/2005 to 06/2005):






Unfortunately I am not a reader of this magazine, so I totally missed the article and can't comment.

I wonder: is the author subscribed to this list?!?!?!?

73,
Paolo IK1ZYW

--
| QRPp-I #707 + www.paolocravero.tk + I QRP #476 |
| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /

a bit of insulation tape on the core will certainly help matters.....
&#92;

mm ali
vu2ali



Quoting Ashhar Farhan <farhan@...>:

the problem with balun is that it has a sharp edges. these edges nick the enamelled wire being passed around. and the wire gets scrapped and touches the core. if more than two wires get nicked, they short, showing high resistance like you said.

you need to be careful in not pulling the wire too tighly around the edges of the balun. a better way might be to coat the corners with a bit of paint.

- farhan

Guys
I am building a BITX and have the rx working very nice.
However, there is a problem of microphics around the detector/af amp.
Ceramics replaced, as per past postings. No change.
I have now traced this to the balun core and find I have a 'short' of
about 60k between one of the windings and the core.
I have tried different wire and smoothing the holes before winding but
every time I get a 'short'.
I have tried a toroid core and that works without the problem.
Interested to know if anyone else has experienced this and if they
found a fix!
73, Steve, G0FUW

What a great site site ... Thanks for flagging it up

Charles G4VSZ
Hon Sec of BRATS Gillingham Kent

Hi Tim,

Yes, built the original design (correct the IC1 pin assigment, pin 5 and 6 is in reverse order), then add everything else to your personal taste.

BITX is an excellent rig, I have built mine to work on 20m (recently) and 40m, suprisingly, with 20m I can hear stations from Japan, US, Hongkong, etc, with 40m i tune to local stations.

If you want to look for further mods to the original design, you can find many ideas on the files sections, also look into the photo sections for some inspiration ( I did this.. :) )

Again, reading back to BITX list archive wont hurt, you can find many ideas, suggestions, troubleshooting and etc, one thing that should be on BITX FAQ is the question about Tap Washer.

Good luck,
Julius

* REPLY SEPARATOR *

On 7/3/2005 at 7:49 PM Tim King wrote:

Hi all,

I have been toying for a while now about building this rig, and just
found the Yahoo group. I am sure there have been changes to the
BITX-20.

Where might I find the version that is most recent?

Should I just build the one on the phonestack website?

()

As a ham on a tight budget, My rigs are homebrew and other peoples
trash. I just revived (sp?) an Yaesu ft-310d, and am working on a
SB-101, both obtained for $100.00 total. I have a duo band psk rig
(20/80) from the warbler kits that I hacked and combined, and now I
want a portable rig for camping. The BITX looks to be up my alley.

Anyway, thanks for letting me join, and thanks in advance for any
and all help!!!

73,

Tim, AG4RZ (ex KG4MQD)





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