Date   
Final modulation video

kc0wox <bitx@...>
 

I've completed the video on the bitx modulation section. This video
uses the bitx board for signals and shows the double sideband signal
out of the balanced modulator, the single sideband signal out of the
filter, and solves the 2nd harmonic of the modulation frequency.
Setting the bfo frequency should be easy after you understand the
fundamentals shown.

The video is at http://golddredgervideo.com/bitx20/bitxssb.wmv

Re: Need help on balun core

ewcheeguan
 

Hi all,


Thanks for the suggestions, i measured and both cores works great
and bandwidth are wide.
million thanks!!

73!
9w2ecg

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

EW

Best method (?) for evaluating unknown cores is to build the winding,
then send a signal through it to a termination. By measuring the input
versus output you should be able to tell which one has best energy
transfer characteristic. The same method works for determining number
of turns required for transmission-line type transformers.

Arv
_._

ewcheeguan wrote:


Hi all,

I purchased 2 type of TV balun yesterday, one type bigger than
other.The big one give 20uH of inductance and the smaller one give
only 2.5uH , I wind it both have 13 turns trifillar.
Which one is the most suitable for balance transformer? can i use
these cores to make L1,L2,L3,L4,L5? (because its cheap !) I have
inductance meter.

Please help!

Thanks!

Regards,
EW
9W2ECG


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

Re: Need help on balun core

Arv Evans
 

EW

Best method (?) for evaluating unknown cores is to build the winding,
then send a signal through it to a termination. By measuring the input
versus output you should be able to tell which one has best energy
transfer characteristic. The same method works for determining number
of turns required for transmission-line type transformers.

Arv
_._

ewcheeguan wrote:



Hi all,

I purchased 2 type of TV balun yesterday, one type bigger than
other.The big one give 20uH of inductance and the smaller one give
only 2.5uH , I wind it both have 13 turns trifillar.
Which one is the most suitable for balance transformer? can i use
these cores to make L1,L2,L3,L4,L5? (because its cheap !) I have
inductance meter.

Please help!

Thanks!

Regards,
EW
9W2ECG

Re: cqbitx blog

Arv Evans
 

Also, <arvevans.livejournal.com> for prototype work on the new Doug
Hendrix Kit.
_._


Sunil Lakhani wrote:


Would you like to share your memmories while building and using the
bitx,then you are most welcome to log on to
http://cqbitx.blogspot.com/ <http://cqbitx.blogspot.com/>
The blog is open for posting to all bitx users and other hams,but
please send your email to sunillakhani123@...
<mailto:sunillakhani123%40gmail.com> for an invitation
to post directly on the blog,this is done to get rid of unwanted
members,who may spam the blog
The blog has been published to keep memmories of all bitx users,so
that they can later cherish the moments with their hands on experiance
with the beautiful bitx.

Re: Need help on balun core

Chris van den Berg
 

Dear EW,
please see http://ph.groups.yahoo.com/group/BITX20/photos/view/132f?
b=11 to find out what I did. Just connect the transformer to your
oscillator and measure difference between input and output. If it is
about equal, the transformer can be used (in my opinion).
Best regards,
Chris.

--- In BITX20@..., "ewcheeguan" <tru168@...> wrote:


Hi all,

I purchased 2 type of TV balun yesterday, one type bigger than
other.The big one give 20uH of inductance and the smaller one give
only 2.5uH , I wind it both have 13 turns trifillar.
Which one is the most suitable for balance transformer? can i
use
these cores to make L1,L2,L3,L4,L5? (because its cheap !) I have
inductance meter.

Please help!

Thanks!

Regards,
EW
9W2ECG

Need help on balun core

ewcheeguan
 

Hi all,

I purchased 2 type of TV balun yesterday, one type bigger than
other.The big one give 20uH of inductance and the smaller one give
only 2.5uH , I wind it both have 13 turns trifillar.
Which one is the most suitable for balance transformer? can i use
these cores to make L1,L2,L3,L4,L5? (because its cheap !) I have
inductance meter.

Please help!

Thanks!

Regards,
EW
9W2ECG

cqbitx blog

Sunil Lakhani <freedomworld123@...>
 

Would you like to share your memmories while building and using the
bitx,then you are most welcome to log on to http://cqbitx.blogspot.com/
The blog is open for posting to all bitx users and other hams,but
please send your email to sunillakhani123@... for an invitation
to post directly on the blog,this is done to get rid of unwanted
members,who may spam the blog
The blog has been published to keep memmories of all bitx users,so
that they can later cherish the moments with their hands on experiance
with the beautiful bitx.

The miracle of the junkbox -- 25 pF trimmer caps

Jim Strohm <n6otq@...>
 

Today I found a forgotten bag of trimmer caps in my
junkbox ("box" is a relative term -- it's a 12 x 20
storage room).

They measure at about 2 pf to 25 pf, and the lead
spacing is the same as the trimmers on the Hendricks
BITX20 board.

This is one day AFTER I soldered some different ones
down ...

Anyway, these will work for thru-hole, or for surface
mount / ugly construction if you bend the leads over.

I need some T37-6 cores, and will trade ...

Jim N6OTQ



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See all the new 2007 cars at Yahoo! Autos.
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Re: Liquid Tape

David Snell <dgsnell@...>
 

Sorry everyone - the liquid tape message was intended for the GQRP group.

I had previously posted the info to the BITX group

Dave M1DGS

Re: Liquid Tape

Allison Parent <kb1gmx@...>
 

--- In BITX20@..., "David Snell" <dgsnell@...> wrote:

I previously sent this to the group. Dave M1DGS
----- Original Message -----
From: m1dgs
To: BITX20@...
Sent: Thursday, July 08, 2004 8:39 AM
Subject: [BITX20] Toriod Q


Has anyone measured the Q of the toroids? I wondered whether it
mattered too much provided the winding details were observed.
For the toroids that are being used as transformers [untuned]
Q is less a factor than distributed capacitance. Most glues
will increase distributed capcitance.

For the tuned circuit toroids the glues not only lower the Q
it may also lower the tuned frequency.

If you must "glue" a suggested material is air cure RTV (silicone
rubber) or better Polystyrene Q dope (liquid polystyrene). The
latter can be made if unable to purchase by desolving clear
polystyrene plastic is a suitable solvent.


Allison

However care has to be taken with the coating materials.
There is an interesting note by Roy Lewallen, W7EL on Mounting
Toroidal Inductors with Common Materials:-
http://www.qrp.pops.net/w7el.htm
His results show that his black sealing tape reduced the Q of his
coil by nearly 40%. Other materials were noted to have lesser effects
although some were worse than others, notably Duco cement. Duco
cement is a nitro cellulose household glue which reduced the Q by
nearly 25%.

Dave M1DGS




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

Liquid Tape

David Snell <dgsnell@...>
 

I previously sent this to the group. Dave M1DGS

----- Original Message -----
From: m1dgs
To: BITX20@...
Sent: Thursday, July 08, 2004 8:39 AM
Subject: [BITX20] Toriod Q


Has anyone measured the Q of the toroids? I wondered whether it
mattered too much provided the winding details were observed.

However care has to be taken with the coating materials.
There is an interesting note by Roy Lewallen, W7EL on Mounting
Toroidal Inductors with Common Materials:-
http://www.qrp.pops.net/w7el.htm
His results show that his black sealing tape reduced the Q of his
coil by nearly 40%. Other materials were noted to have lesser effects
although some were worse than others, notably Duco cement. Duco
cement is a nitro cellulose household glue which reduced the Q by
nearly 25%.

Dave M1DGS

Re: BITX calling frequency

farhan@...
 

two things here:

1. i no longer consider myself as the 'father' of bitx. i just happen to make the first one. it has been refined and reviewed so many times that i think it does a great disservice to this group to give credit for the success of bitx to me.

2. i think the idea of a calling frequency is very fine. 14.285 is already the qrp calling frequency. more than a calling frequency, it would be really fine if we could have a bitx net. it is liddy to use a calling frequency for net. if anyone has a frequency and time in mind, we can go for it. given the qrp nature of bitx, it is probably a good idea to have the net control based out of europe.

- farhan

On Mon, 26 Feb 2007, Mike W wrote:

Nice idea Michel, dot two eight five is as good as any other. C U there ?.

On 26 Feb 2007 at 11:23, Michel Van Der Biest wrote:

Hello all

Many people in the world are now using the BITX 20.
Why not an international calling frequency for us ?
It is probably a good solution to establish contact and for technical
discussion.
Personally, from France, I am calling on 14.285 Mhz.

Maybe,Ashhar, the father of this nice transceiver has his idea ?

With my best 73 from France.

Michel
F6FEO

Re: losses in xtal filter

Chris van den Berg
 

If the impedance is really the problem, a possible solution can be
found like http://ph.groups.yahoo.com/group/BITX20/photos/view/132f?b=7
Good luck,
Chris.

Re: BITX calling frequency

Mike W <mike@...>
 

Nice idea Michel, dot two eight five is as good as any other. C U there ?.

On 26 Feb 2007 at 11:23, Michel Van Der Biest wrote:

Hello all

Many people in the world are now using the BITX 20.
Why not an international calling frequency for us ?
It is probably a good solution to establish contact and for technical
discussion.
Personally, from France, I am calling on 14.285 Mhz.

Maybe,Ashhar, the father of this nice transceiver has his idea ?

With my best 73 from France.

Michel
F6FEO

BITX calling frequency

Michel Van Der Biest <f6feo@...>
 

Hello all

Many people in the world are now using the BITX 20.
Why not an international calling frequency for us ?
It is probably a good solution to establish contact and for technical discussion.
Personally, from France, I am calling on 14.285 Mhz.

Maybe,Ashhar, the father of this nice transceiver has his idea ?

With my best 73 from France.

Michel
F6FEO

Re: losses in xtal filter

luuk_h <luuk_h@...>
 

Thanx for the help guys ,
First,I will try to get better xtals. Maybe someone knows a internet
shop that sells 9 Mhz ground tone xtals. If so please tell me.
If that does not help then I will try the auto transformer
suggestion. I will try it on the bench anyway.
Another bidirectional amp will be build if nothing helps.

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

Hi all,

I am building a bitx IF strip using 9 Mhz xtals. My problem is
that
the filter is lossy. The losses are 18 db.
Does anyone know what could be the problem?

I have use 27 Mhz overtone xtals. They match within 100Hz.
The bandwidth is Ok: 2Khz @ 3 db.The signal sounds ok , it is just
weak. I bought 15 of them. they are from 1 batch.

Some 9.8 Mhz ground tone xtals were tried as well. That filter was
much better. The losses were 6 db.

I hope anyone can help

73
PA3EMY

Re: TV baluns

Bruce Conner
 

--- In BITX20@..., Jim Kortge <jokortge@...> wrote:
The BN2402 style cores made with 43 material are available from Diz,
W8DIZ at kitandparts.com and also from Brad, AA1IP. The last time I
bought
BN2402 cores from Brad they were 20 pieces for $1.00 plus shipping
which was
nominal. Both sources are highly recommended.
Jim,

I've ordered from kitsandparts before and was very satisfied with both
the price and quick service. Thanks for the details on what to order!

Bruce
WB8OGK

Re: TV baluns

larry allen <larya@...>
 

I found it... thanks..
Larry ve3fxq

----- Original Message -----
From: "Jim Kortge" <jokortge@...>
To: <BITX20@...>
Sent: Sunday, February 25, 2007 11:21 AM
Subject: Re: [BITX20] TV baluns


larry allen wrote:
Hi...
Would you give the a better web address?
www.kitandparts.com
doesn't work...
Larry ve3fxq
Yes, its at http://kitsandparts.com/
72,
Jim, K8IQY

Re: TV baluns

Jim Kortge <jokortge@...>
 

larry allen wrote:
Hi...
Would you give the a better web address?
www.kitandparts.com
doesn't work...
Larry ve3fxq
Yes, its at http://kitsandparts.com/

72,

Jim, K8IQY

Re: TV baluns

Jim Strohm <n6otq@...>
 

--- larry allen <larya@...> wrote:

Hi...
Would you give the a better web address?
www.kitandparts.com
doesn't work...
Googling on W8DIZ returns www.kitsandparts.com/ as the
first result.

Jim N6OTQ



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