I'm looking for a small hand held signal generator to cover the 1 ghx to 2
range. Output need be at least 1 watt into 50 ohms. The lower the price,
the better.
Any suggestions?

Hul

On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
wrote:

> I'm looking for a small hand held signal generator to cover the 1 ghx to 2
>range. Output need be at least 1 watt into 50 ohms. The lower the price,
>the better.

Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
cellular, hydrogen line, radio astronomy, satellite communications,
maritime, radiometry, etc. You'll find the US allocations listed at:
Pg 32 - 39. Which of these were you planning to jam?

>Any suggestions?
>Hul

Perhaps find something else to do?

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 10 Jul 2021 16:30:48 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

Oops. I forgot to include the link.

>You'll find the US allocations listed at:
<https://www.fcc.gov/file/21474/download>
>Pg 32 - 39. Which of these were you planning to jam?

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
wrote:

> I'm looking for a small hand held signal generator to cover the 1 ghx to 2
>range. Output need be at least 1 watt into 50 ohms. The lower the price,
>the better.
> Any suggestions?
>
>Hul

1W?? Seems a *hell* of a lot for a sig gen!

jeff - this is for tuning an antenna for a gps reciever.

Hul

Jeff Liebermann <jeffl@cruzio.com> wrote:
> On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
> wrote:

> > I'm looking for a small hand held signal generator to cover the 1 ghx to 2
> >range. Output need be at least 1 watt into 50 ohms. The lower the price,
> >the better.

> Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
> cellular, hydrogen line, radio astronomy, satellite communications,
> maritime, radiometry, etc. You'll find the US allocations listed at:
> Pg 32 - 39. Which of these were you planning to jam?

> >Any suggestions?
> >Hul

> Perhaps find something else to do?

> --
> Jeff Liebermann jeffl@cruzio.com
> PO Box 272 http://www.LearnByDestroying.com
> Ben Lomond CA 95005-0272
> Skype: JeffLiebermann AE6KS 831-336-2558

jeff - this for tuning an antenna for a gps reciever.

Hul

Jeff Liebermann <jeffl@cruzio.com> wrote:
> On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
> wrote:

> > I'm looking for a small hand held signal generator to cover the 1 ghx to 2
> >range. Output need be at least 1 watt into 50 ohms. The lower the price,
> >the better.

> Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
> cellular, hydrogen line, radio astronomy, satellite communications,
> maritime, radiometry, etc. You'll find the US allocations listed at:
> Pg 32 - 39. Which of these were you planning to jam?

> >Any suggestions?
> >Hul

> Perhaps find something else to do?

> --
> Jeff Liebermann jeffl@cruzio.com
> PO Box 272 http://www.LearnByDestroying.com
> Ben Lomond CA 95005-0272
> Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 11 Jul 2021 15:24:37 -0000 (UTC), Hul Tytus <ht@panix.com>
wrote:

>jeff - this for tuning an antenna for a gps reciever.

You don't need a whole Watt for that.

On 11/07/2021 16:22, Hul Tytus wrote:
> jeff - this is for tuning an antenna for a gps reciever.
>
> Hul

It is extremely antisocial to jam that band. Unless you are inside a
Faraday cage so that there is no leakage of your signal to the outside
world then you deserve to be prosecuted for doing it.

What is wrong with adjusting it to maximise signal strength from the
satellites overhead? Even a few mW CW TX might blind nearby GPS devices.

> Jeff Liebermann <jeffl@cruzio.com> wrote:
>> On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
>> wrote:
>
>>> I'm looking for a small hand held signal generator to cover the 1 ghx to 2
>>> range. Output need be at least 1 watt into 50 ohms. The lower the price,
>>> the better.
>
>> Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
>> cellular, hydrogen line, radio astronomy, satellite communications,
>> maritime, radiometry, etc. You'll find the US allocations listed at:
>> Pg 32 - 39. Which of these were you planning to jam?
>
>>> Any suggestions?
>>> Hul
>
>> Perhaps find something else to do?

+1

You should not be deliberately radiating RF into protected bands!

--
Regards,
Martin Brown

Hul Tytus wrote:
> jeff - this for tuning an antenna for a gps reciever.
>
> Hul
>
> Jeff Liebermann <jeffl@cruzio.com> wrote:
>> On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
>> wrote:
>
>>> I'm looking for a small hand held signal generator to cover the 1 ghx to 2
>>> range. Output need be at least 1 watt into 50 ohms. The lower the price,
>>> the better.
>
>> Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
>> cellular, hydrogen line, radio astronomy, satellite communications,
>> maritime, radiometry, etc. You'll find the US allocations listed at:
>> Pg 32 - 39. Which of these were you planning to jam?
>
>>> Any suggestions?
>>> Hul
>
>> Perhaps find something else to do

If you have a spectrum analyzer handy (or a SDR dongle and some free
s/w), you can just point the antenna at the sun and tweak it up for
maximum signal.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

Nothing fancy in this frequency range. The plan was to use
a handy Wavetek device but it's not working.

Hul

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
> Hul Tytus wrote:
> > jeff - this for tuning an antenna for a gps reciever.
> >
> > Hul
> >
> > Jeff Liebermann <jeffl@cruzio.com> wrote:
> >> On Sat, 10 Jul 2021 21:17:55 -0000 (UTC), Hul Tytus <ht@panix.com>
> >> wrote:
> >
> >>> I'm looking for a small hand held signal generator to cover the 1 ghx to 2
> >>> range. Output need be at least 1 watt into 50 ohms. The lower the price,
> >>> the better.
> >
> >> Between 1 and 2 GHz are aviation, radar, navigation, ham radio,
> >> cellular, hydrogen line, radio astronomy, satellite communications,
> >> maritime, radiometry, etc. You'll find the US allocations listed at:
> >> Pg 32 - 39. Which of these were you planning to jam?
> >
> >>> Any suggestions?
> >>> Hul
> >
> >> Perhaps find something else to do

> If you have a spectrum analyzer handy (or a SDR dongle and some free
> s/w), you can just point the antenna at the sun and tweak it up for
> maximum signal.

> Cheers

> Phil Hobbs

> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510

> http://electrooptical.net
> http://hobbs-eo.com

On Sun, 11 Jul 2021 15:22:41 -0000 (UTC), Hul Tytus <ht@panix.com>
wrote:

>jeff - this is for tuning an antenna for a gps reciever.
>Hul

1 watt is far too much RF power for testing antennas. GPS signals are
easily trashed by interference. For example, GPS was dead in the Moss
Landing, CA harbor area because of an oscillating amplified TV
antenna. My guess is about 10 milliwatts of RF power.
<https://www.gpsworld.com/the-hunt-rfi/>
<http://www.learnbydestroying.com/jeffl/GPS%20Jamming%20Moss%20Landing/>
When I work with small antennas, it's usually with low power, in a
shielded building, in a screen room, or using a screened enclosure.
This is as much to prevent interference to GPS (or other service)
users, as it is to reduce interference from strong signals in the same
frequency range or adjacent bands.

Kinda sounds like you're a hobbyist and are not going to buy expensive
test equipment. So, a minimalist setup should suffice for GPS
antennas. You probably want a VNA (vector network analyzer). I
haven't tried this model, but it does go up to 3GHz and *SHOULD* work
at GPS frequencies:
<https://nanorfe.com/nanovna-v2.html>
You'll also need some SMA connectors, cables, adapters, and
terminations. About $60 and up.

I made the mistake of buying a NanoVNA V1 model clone, that proved to
be junk. Avoid the clones unless you're sure that they work.
<https://nanorfe.com/nanovna-versions.html>
<https://nanorfe.com/nanovna-v2-faq.html#clone>
Also, no matter where you buy one, you will probably need to update
the firmware.

I don't know what type of GPS antenna you're designing. Designs vary
depending on how the GPS is used. For example, a hand held receiver
will probably use a patch antenna. For fixed installations on
rooftops, a wire antenna (quadrifilar helical) gives better gain near
the horizon. For fixed locations, a ground plane will reduce ground
reflections. For precision surveying, a choke ring reduces multipath
and ground reflection problems, while maintaining an accurate phase
center:
<https://www.google.com/search?q=gps+antenna+choke+ring&tbm=isch>

For antennas: Small size, high gain, wide bandwidth. Pick any two.

Good luck.

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 11 Jul 2021 15:02:12 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>If you have a spectrum analyzer handy (or a SDR dongle and some free
>s/w), >you can just point the antenna at the sun and tweak it up for
>maximum signal.

Yep, that works. However, I didn't want to setup an outdoor lab and
limit my hours to when the sun is shining. Besides, I do my best work
under cover of darkness.

The really cheap R820T2 SDR tuners will only tune up to 1766 MHz.
That's sufficiently high for the GPS bands (1610 MHz max). However,
I've seen receivers with poor sensitivity where anything above about
1GHz is buried in the noise.

I have two of these noise sources:
<https://www.ebay.com/itm/284289625592>
The output isn't very flat but works ok over narrow bandwidths.
However, from 1100 to 1610 MHz frequency range needed for GPS, I the
noise drops -5dB at the high end. For that, a spectrum analyzer with
a normalizer feature is required. I cheat and just rotate the CRT
trace against the grid.

Before the days of cheap VNA's, I used a return loss bridge:
<https://www.google.com/search?q=return+loss+bridge&tbm=isch>
<https://www.google.com/search?q=reflection+coefficient+bridge&tbm=isch>
<https://www.qsl.net/n9zia/rlb/texscan.png>
It would directly indicate return loss or VSWR, but would not show
whether the reactance was inductive or capacitive. That made tweaking
antennas a bit of a challenge, but after a few mistakes, I could tell
which direction I should tweak. Besides the bridge, all that was
needed was an RF sweep generator with DC horizontal output, an RF
detector (diode), DC log amp, and almost any oscilloscope. If all
that is needed is the frequency of minimum VSWR, then a bridge is
sufficient.

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558