RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Homebrew (https://www.radiobanter.com/homebrew/)
-   -   Is it really hard? - VHF RX (https://www.radiobanter.com/homebrew/21682-really-hard-vhf-rx.html)

Julian Vereker November 20th 03 10:06 AM

Is it really hard? - VHF RX
 
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



G.Beat November 20th 03 01:00 PM

"Julian Vereker" wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



Julian,

I do not know where you are looking.

IF you have an HF transceiver there are VHF transverters available from both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/

Greg
w9gb



G.Beat November 20th 03 01:00 PM

"Julian Vereker" wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



Julian,

I do not know where you are looking.

IF you have an HF transceiver there are VHF transverters available from both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/

Greg
w9gb



R J Carpenter November 20th 03 02:54 PM


"G.Beat" wrote in message
news:LV2vb.192288$mZ5.1420438@attbi_s54...
"Julian Vereker" wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



Julian,

I do not know where you are looking.

IF you have an HF transceiver there are VHF transverters available from

both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/




Or, better, Down-East Microwave in New Jersey. They sell kits for 50 MHz
and up, up, up.

http://www.downeastmicrowave.com/

Reliable outfit, reliable gear. They've been at it for many years.





R J Carpenter November 20th 03 02:54 PM


"G.Beat" wrote in message
news:LV2vb.192288$mZ5.1420438@attbi_s54...
"Julian Vereker" wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



Julian,

I do not know where you are looking.

IF you have an HF transceiver there are VHF transverters available from

both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/




Or, better, Down-East Microwave in New Jersey. They sell kits for 50 MHz
and up, up, up.

http://www.downeastmicrowave.com/

Reliable outfit, reliable gear. They've been at it for many years.





Joe McElvenney November 20th 03 07:24 PM

Julian,

No, it is not particularly difficult to build for 144/432 MHz.
All you need are good low-noise devices, short leads and a little
determination, which I'm sure you have plenty of. For starters,
why not have a look at the simple 144 to 30MHz converter on this
site -


http://homepage.tinet.ie/~ei9gq/vhf_conv.html


This should give you an idea of the style of construction
needed. The only component that you may have trouble with is the
overtone crystal but there are other ways of achieving the same
end.


73 de Joe, G3LLV



Joe McElvenney November 20th 03 07:24 PM

Julian,

No, it is not particularly difficult to build for 144/432 MHz.
All you need are good low-noise devices, short leads and a little
determination, which I'm sure you have plenty of. For starters,
why not have a look at the simple 144 to 30MHz converter on this
site -


http://homepage.tinet.ie/~ei9gq/vhf_conv.html


This should give you an idea of the style of construction
needed. The only component that you may have trouble with is the
overtone crystal but there are other ways of achieving the same
end.


73 de Joe, G3LLV



Julian Vereker November 23rd 03 09:25 AM

I do not know where you are looking.
Google of course, but it seems getting worse and worse...

IF you have an HF transceiver there are VHF transverters available from both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/

Fine, but notice, please from where I am writing ( .pl is for Poland).
The costs of shipping, a local tax and zoll payments will rise price
about 75%. That's first notice. The second one is I want to build it
myself. That's why I choose homebrewing group.



Julian Vereker November 23rd 03 09:25 AM

I do not know where you are looking.
Google of course, but it seems getting worse and worse...

IF you have an HF transceiver there are VHF transverters available from both
Ten-Tec and Elecraft

http://www.tentec.com/Amateur.htm

Elecraft will have a 440 transverter available in the near future
http://www.elecraft.com/XV/XV.htm

Hamtronics - VHF and UHF kits since 1962
Receive converter kits (less enclosure) are only $ 49 USD
http://www.hamtronics.com/

Fine, but notice, please from where I am writing ( .pl is for Poland).
The costs of shipping, a local tax and zoll payments will rise price
about 75%. That's first notice. The second one is I want to build it
myself. That's why I choose homebrewing group.



Julian Vereker November 23rd 03 09:30 AM

No, it is not particularly difficult to build for 144/432 MHz.
All you need are good low-noise devices, short leads and a little
determination, which I'm sure you have plenty of. For starters,
why not have a look at the simple 144 to 30MHz converter on this
site -


http://homepage.tinet.ie/~ei9gq/vhf_conv.html

Thanks for the link. Something lil' more complex ?

This should give you an idea of the style of construction
needed. The only component that you may have trouble with is the
overtone crystal but there are other ways of achieving the same
end.

We got good crystal producer here in Poland called Omig, BTW they are
IBM supplier I think I'll find something.




Julian Vereker November 23rd 03 09:30 AM

No, it is not particularly difficult to build for 144/432 MHz.
All you need are good low-noise devices, short leads and a little
determination, which I'm sure you have plenty of. For starters,
why not have a look at the simple 144 to 30MHz converter on this
site -


http://homepage.tinet.ie/~ei9gq/vhf_conv.html

Thanks for the link. Something lil' more complex ?

This should give you an idea of the style of construction
needed. The only component that you may have trouble with is the
overtone crystal but there are other ways of achieving the same
end.

We got good crystal producer here in Poland called Omig, BTW they are
IBM supplier I think I'll find something.




Paul Keinanen December 10th 03 03:12 PM

On Sun, 21 Dec 2003 20:34:13 +0800, "Richard Hosking"
wrote:

For CW you need a tunable VFO and this is not easy with reasonable stability
You wiull have to use an HF transceiver as a tunable IF


If you are _only_ interested in the 2m CW band around 144.050 MHz, a
VXO should give a sufficient tuning range.

A fundamental mode crystal (i.e. below 20 MHz) can be tuned by
500-1000 ppm with a series inductance and variable capacitor. This
should give a 70-150 kHz tuning range on the 2m band.

If a 10.7 MHz IF with low side injection is used, the required LO
frequency would be about 133 MHz is needed, which can be done with a
14.82 Mhz crystal and two triplers or with 16.67 MHz crystal and three
triplers. High side injection should also be checked, since these may
give crystal frequencies that are easier to obtain.

These days the doublers and triplers can be quite easily implemented
with MMICs (such as MAR-x series) and bandpass sections between the
stages.

MMIC:s have reasonable noise figures for the 2m band even as RF front
end amplifiers, but sufficient front end selectivity is often required
to avoid overload problems if the gain is very high.

Paul OH3LWR


Paul Keinanen December 10th 03 03:12 PM

On Sun, 21 Dec 2003 20:34:13 +0800, "Richard Hosking"
wrote:

For CW you need a tunable VFO and this is not easy with reasonable stability
You wiull have to use an HF transceiver as a tunable IF


If you are _only_ interested in the 2m CW band around 144.050 MHz, a
VXO should give a sufficient tuning range.

A fundamental mode crystal (i.e. below 20 MHz) can be tuned by
500-1000 ppm with a series inductance and variable capacitor. This
should give a 70-150 kHz tuning range on the 2m band.

If a 10.7 MHz IF with low side injection is used, the required LO
frequency would be about 133 MHz is needed, which can be done with a
14.82 Mhz crystal and two triplers or with 16.67 MHz crystal and three
triplers. High side injection should also be checked, since these may
give crystal frequencies that are easier to obtain.

These days the doublers and triplers can be quite easily implemented
with MMICs (such as MAR-x series) and bandpass sections between the
stages.

MMIC:s have reasonable noise figures for the 2m band even as RF front
end amplifiers, but sufficient front end selectivity is often required
to avoid overload problems if the gain is very high.

Paul OH3LWR


Grumpy OM December 11th 03 03:22 PM

(Julian Vereker) wrote in message . com...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



I've been designing xmitters for low power fast scan video on 70cm.
For an rx I use an old vcr. I put a 10 turn pot on the BT terminal of
the tuner. Works fine.
Grumpy

Grumpy OM December 11th 03 03:22 PM

(Julian Vereker) wrote in message . com...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?



I've been designing xmitters for low power fast scan video on 70cm.
For an rx I use an old vcr. I put a 10 turn pot on the BT terminal of
the tuner. Works fine.
Grumpy

Richard Hosking December 21st 03 12:34 PM

For CW you need a tunable VFO and this is not easy with reasonable stability
You wiull have to use an HF transceiver as a tunable IF

Richard


Julian Vereker wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?





Richard Hosking December 21st 03 12:34 PM

For CW you need a tunable VFO and this is not easy with reasonable stability
You wiull have to use an HF transceiver as a tunable IF

Richard


Julian Vereker wrote in message
om...
Hello,

I'm trying to find some simple receiver (or at least a converter)
project for 440 or 144 MHz to build. I'm interested in CW mode. But
there's nothing.
Is it very hard to build something for 70 cm or there are another
reasons, that I can't find anything?






All times are GMT +1. The time now is 05:04 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com