Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old December 4th 03, 03:55 AM
PDRUNEN
 
Posts: n/a
Default RF amplifier

Hi Group,

My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I need a
simple circuit to cover HF which will boost this up to 500mW. I would like to
try out the signal generator as a low power CW transmitter.

I have a few CBs around that I could use the RF amp to get me on 10 meter but I
am not sure of the drive level. I am not sure if this amp would work below 24
MHz without re-tuning.

Anyone have a simple wideband circuit that could cover 3.5 to 28 MHz?

de KJ4UO
  #4   Report Post  
Old December 4th 03, 12:19 PM
Sverre Holm
 
Posts: n/a
Default

My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I
need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's with
it, but after several RST xx8 reports I found that the signal generator had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za


  #5   Report Post  
Old December 4th 03, 12:19 PM
Sverre Holm
 
Posts: n/a
Default

My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I
need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's with
it, but after several RST xx8 reports I found that the signal generator had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za




  #6   Report Post  
Old December 4th 03, 12:35 PM
Ghost writer
 
Posts: n/a
Default

"Sverre Holm" wrote in message
...
My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I

need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's

with
it, but after several RST xx8 reports I found that the signal generator

had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has

very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this

is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za



One must wonder about another "possible" problem as well. If even a fraction
of transmitted RF were to get back into the sig gen, it may upset the
balance as well causing any sort of problems. Much like when RF gets back
into a Power Supply situated close by - creates hum and so on - on the
signal. Some Sig Gens may not have enough shielding to protect from this.
Their shielding may very well prevent signals from leaking OUT when testing
from it's own source, but not designed to fight off Transmitted RF getting
back into it. I'm not saying those things WILL happen, but certainly
possible. Otherwise, the idea is interesting and I'm sure many others
unmentioned have thought of or have actually tried it. I being one.

On another note along these lines, though I didn't see it or hear it, I
heard a ham on 2 meters once who claimed to take a Bearcat scanner - a 250
model I believe.. and used it in much the same manner... I'd love to have
seen and heard it up close. G.W.


  #7   Report Post  
Old December 4th 03, 12:35 PM
Ghost writer
 
Posts: n/a
Default

"Sverre Holm" wrote in message
...
My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I

need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's

with
it, but after several RST xx8 reports I found that the signal generator

had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has

very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this

is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za



One must wonder about another "possible" problem as well. If even a fraction
of transmitted RF were to get back into the sig gen, it may upset the
balance as well causing any sort of problems. Much like when RF gets back
into a Power Supply situated close by - creates hum and so on - on the
signal. Some Sig Gens may not have enough shielding to protect from this.
Their shielding may very well prevent signals from leaking OUT when testing
from it's own source, but not designed to fight off Transmitted RF getting
back into it. I'm not saying those things WILL happen, but certainly
possible. Otherwise, the idea is interesting and I'm sure many others
unmentioned have thought of or have actually tried it. I being one.

On another note along these lines, though I didn't see it or hear it, I
heard a ham on 2 meters once who claimed to take a Bearcat scanner - a 250
model I believe.. and used it in much the same manner... I'd love to have
seen and heard it up close. G.W.


  #8   Report Post  
Old December 5th 03, 07:01 AM
Richard Hosking
 
Posts: n/a
Default

I thought the Leader Sig Gens were free running and not very stable. Maybe
it is a new model.
If you simply want a CW TX, why not build the VFO as well?
There are plenty of designs around.
If you do want to use the RF gen , you could always follow it with a low
pass filter.

Richard


Sverre Holm wrote in message
...
My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I

need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's

with
it, but after several RST xx8 reports I found that the signal generator

had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has

very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this

is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za




  #9   Report Post  
Old December 5th 03, 07:01 AM
Richard Hosking
 
Posts: n/a
Default

I thought the Leader Sig Gens were free running and not very stable. Maybe
it is a new model.
If you simply want a CW TX, why not build the VFO as well?
There are plenty of designs around.
If you do want to use the RF gen , you could always follow it with a low
pass filter.

Richard


Sverre Holm wrote in message
...
My wavetek sig gen covers 100KHz to 512 MHz and puts out about 10mW. I

need a
simple circuit to cover HF which will boost this up to 500mW. I would

like to
try out the signal generator as a low power CW transmitter.


I did something similar when I first was licenced in 2001, but I would not
recommend it now.

I used my Leader LSG-216 signal generator as a VFO followed by a 1 Watt
amplifier that I put together myself. It worked and I had several QSO's

with
it, but after several RST xx8 reports I found that the signal generator

had
hum modulation and some jitter. I have later learnt that this is almost
inherent in a synthesizer which covers a large frequency range. It has

very
large VCO gain: MHz/Volts - change in frequency per change in voltage in
order to cover the large frequency range. But this also makes it very
sensitive to noise in the control voltage.

As a signal generator, i.e. a tool for aligning circuits and so on, this

is
not a problem.


Sverre LA3ZA
www.qsl.net/la3za




Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: RF Concepts 2 meter all-mode amplifier RFC 2-417 Jim Young Equipment 1 March 10th 11 08:49 AM
Loop Antenna for Class-E amplifier Marc Battyani Antenna 19 May 15th 04 06:48 PM
How Clean is a Palomar 300A? mike Equipment 8 August 9th 03 11:23 PM
FS: RF Concepts 2 meter all-mode amplifier RFC 2-417 Jim Young Equipment 0 July 21st 03 05:39 PM


All times are GMT +1. The time now is 02:24 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017