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First real QSO with 150 mW

 

Hi all,
last weekend, I erected a dipole antenne for 18 MHz.
I had finished the BITX17 without the IRF510, the output power of
the used 2N2219 is about 150 mW.
Some tests with PA3CWS (distance about 7 km) showed that the
modulation sounds good and that it really works.
Tonight, I called a SM0 station that was calling CQ on the band and
he answered my call with a good report on signal strength and
modulation! The distance is more then 1000 km I gues!
One of the next steps will be to put it all in a box and to add the
final PA stage.

What is the status of all the other builders? ;-)
Regards,
Chris.
Arvid Evans
 

Chris

CONGRATULATIONS on your new BITX17 and QSOs with it.
1000 Km on 150 mw...that is about 6000 Km per watt.
Think what you can do when you get the full 8 watts
on the air!

73s
Arv - K7HKL

--- In BITX20@..., "vdberghak" <vdberghak@z...> wrote:
Hi all,
last weekend, I erected a dipole antenne for 18 MHz.
I had finished the BITX17 without the IRF510, the output power of
the used 2N2219 is about 150 mW.
Some tests with PA3CWS (distance about 7 km) showed that the
modulation sounds good and that it really works.
Tonight, I called a SM0 station that was calling CQ on the band and
he answered my call with a good report on signal strength and
modulation! The distance is more then 1000 km I gues!
One of the next steps will be to put it all in a box and to add the
final PA stage.

What is the status of all the other builders? ;-)
Regards,
Chris.
Hans Summers
 

What is the status of all the other builders? ;-)
Little progress here. My BITX20 is essentially complete (see my photos under
G0UPL directory) and awaits debugging and alignment.

I have very little spare time, and too many other projects going on at the
same time. I have converted my 1-valve CW transmitter for 30m operation and
had a couple of QSO's on 10.125MHz. See
for some pictures. I am
also planning to have my 30m QRSS beacon QRV again in the next few days, see
.

I have also been developing a combined frequency counter and Huff Puff
stabiliser for the BITX20 VFO (not that it seems particularly unstable
anyway!), that will also be suitable for many other applications.

Eventually I will complete the BITX20, the final 1% effort that is needed
;-)

=============================================
FOR ARV ONLY: Arv I do not think you are able to receive any emails from me
unless they come via the group. Strange situation. I have been trying to
reply to your emails, without success. I created a new private-membership
Yahoo group , if you can join that then
I'll try sending to that, and if it works like this group then you'll be
able to copy me Ok.
=============================================
73 Hans G0UPL
Hans Summers
 

OT: MESSAGE FOR ARV EVANS:

Sorry to all the group for this message, I am trying to communicate with Arv
K7HKL but I am failing to do so via ordinary email.

Arv, I think that when I created the g0upl group I set it to be hidden from
the directory. I deleted it to try again but Yahoo would not let me use the
same name. Therefore I created a new group called k7hkl - could you try
accessing and subscribing to:



And let's see if this time it works.

Apologies again to everyone else

-----Original Message-----
From: vdberghak [mailto:vdberghak@...]
Sent: 23 August 2004 22:40
To: BITX20@...
Subject: [BITX20] First real QSO with 150 mW


Hi all,
last weekend, I erected a dipole antenne for 18 MHz.
I had finished the BITX17 without the IRF510, the output power of
the used 2N2219 is about 150 mW.
Some tests with PA3CWS (distance about 7 km) showed that the
modulation sounds good and that it really works.
Tonight, I called a SM0 station that was calling CQ on the band and
he answered my call with a good report on signal strength and
modulation! The distance is more then 1000 km I gues!
One of the next steps will be to put it all in a box and to add the
final PA stage.

What is the status of all the other builders? ;-)
Regards,
Chris.





Yahoo! Groups Links
market10gardener
 

--- In BITX20@..., "vdberghak" <vdberghak@z...> wrote:
What is the status of all the other builders? ;-)
Progress at this end is slower than hoped but the rx is now working
very well.
Two minor points.
1. The middle section of the band pass filter needed a bit more
reactance. An extra 10pf across the capacitor was fine. An extra turn
or two on the tap washer would have done.
2. A 0.001uf cap. across the 4.7K pot,at the circuit board end of the
screened lead eliminated some RF break through and stopped the pot
from making a scratchy sound.
I wasted some time setting the BFO as I had foolishly assumed the
filter would centre on 10 MHz and set the freq. at 9.998500. It was
only later that I realised that Heinz, OE5EEP had done all the work
and that the mid point of the filter was about 9.996450. A BFO
setting of 9.996300 worked perfectly. Cant wait to get the PA built.
Incidentally, checking the R/T switch there is a loud squeak on
turning back from tx to rx. Has anyone else found this?
John G0UCP
 

Incidentally, checking the R/T switch there is a loud squeak on
turning back from tx to rx. Has anyone else found this?
John G0UCP
Hi,
I have the same experience.
I thought it has someting to do with the way I switch over, three
wires with clamps between the circuit and a switch, but it seems
that it is a timing problem?
So now you know you are not the only one who has it, does not mean
we have a solution.
Any comments from others?
Chris.
Arv Evans
 

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I too have the same problem, maybe worse because I'm using a VOX driving my switchover relays and it affects the VOX setting.? My fix for the symptom was to add a relay? and switch the speaker lead back ON after the Tx voltage has totally died.? However, this is not a fix for the problem.? Instead it is just treating the symptom.? We may have to resort to adding a few milliseconds delay between TX-OFF and RX-ON.

Arv
_._
On Wed, 2004-08-25 at 11:34, vdberghak wrote:

> Incidentally, checking the R/T switch there is a loud squeak on
> turning back from tx to rx. Has anyone else found this?
> John? G0UCP

Hi,
I have the same experience.
I thought it has someting to do with the way I switch over, three
wires with clamps between the circuit and a switch, but it seems
that it is a timing problem?
So now you know you are not the only one who has it, does not mean
we have a solution.
Any comments from others?
Chris.


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Arvid Evans
 

John & Chris

I just took a good look at the schematic, and it seems that the Mike
amp's 50 MFD decoupling capacitor (the one connected to 12 V via a 220
ohm resistor) may be storing enough voltage to allow mike-to-RX-audio
feedback when we switch from TX to RX (i.e both the mike amp and the
RX audio section are on at the same time). You might try lowering
it's value (maybe something like 22 MFD or even 10 MFD) to see if this
makes the changeover squeek shorter, or eliminates it completely.

Maybe we will have to ground the TX 12 Volt line when we are in RX
mode. This will require an additional switch or relay contact pair,
but right now I don't see any other simple way to solve this.

Arv
_._

--- In BITX20@..., Arv Evans <arvevans@e...> wrote:
I too have the same problem, maybe worse because I'm using a VOX driving
my switchover relays and it affects the VOX setting. My fix for the
symptom was to add a relay and switch the speaker lead back ON after
the Tx voltage has totally died. However, this is not a fix for the
problem. Instead it is just treating the symptom. We may have to
resort to adding a few milliseconds delay between TX-OFF and RX-ON.

Arv
_._
On Wed, 2004-08-25 at 11:34, vdberghak wrote:

Incidentally, checking the R/T switch there is a loud squeak on
turning back from tx to rx. Has anyone else found this?
John G0UCP
Hi,
I have the same experience.
I thought it has someting to do with the way I switch over, three
wires with clamps between the circuit and a switch, but it seems
that it is a timing problem?
So now you know you are not the only one who has it, does not mean
we have a solution.
Any comments from others?
Chris.


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