On 13/10/2018 20:43, Jeff Liebermann wrote:

I understand how antenna work and how to predict performance. I can
even do it without 4NEC2 or other antenna modeling program. For
example, the uglier the antenna, the better it works. Antennas that
are more expensive, bigger, and in violation of local building
ordinances, work the best. Experimental prototype antennas always
work while the production versions never seem to work as well. If
there are two ways to assemble an antenna, the wrong way will have
higher gain, lower VSWR, or both. High gain, small size, or wide
bandwidth; pick any two. Using these rules of thumb and others,
anyone can predict how well an antenna will perform by inspection and
without using computer models, Smith charts, or tedious calculations.

WHS

There has been much talk on UKRA in the recent past about the merits or
otherwise of various makes and models of VNAs. It's my view that the
point of having an Amateur licence is to be able to transmit signals
intended to be received by another station. One of the alleged virtues
of a VNA is to be able to set up one's aerial system. However, I
maintain that using cheap torch bulbs is an equally valid indicator of
the state of tune of one's station, and that a distant station cannot
tell the difference between a system set up with the aid of a VNA and
one set up with the aid of a torch bulb or two.


--
Spike

"Nearly all men can stand adversity,
but if you want to test a man's character,
give him an internet group to manage"

On 14/10/2018 09:49, Spike wrote:
On 13/10/2018 20:43, Jeff Liebermann wrote:

I understand how antenna work and how to predict performance. I can
even do it without 4NEC2 or other antenna modeling program. For
example, the uglier the antenna, the better it works. Antennas that
are more expensive, bigger, and in violation of local building
ordinances, work the best. Experimental prototype antennas always
work while the production versions never seem to work as well. If
there are two ways to assemble an antenna, the wrong way will have
higher gain, lower VSWR, or both. High gain, small size, or wide
bandwidth; pick any two. Using these rules of thumb and others,
anyone can predict how well an antenna will perform by inspection and
without using computer models, Smith charts, or tedious calculations.

WHS

There has been much talk on UKRA in the recent past about the merits or
otherwise of various makes and models of VNAs. It's my view that the
point of having an Amateur licence is to be able to transmit signals
intended to be received by another station. One of the alleged virtues
of a VNA is to be able to set up one's aerial system. However, I
maintain that using cheap torch bulbs is an equally valid indicator of
the state of tune of one's station, and that a distant station cannot
tell the difference between a system set up with the aid of a VNA and
one set up with the aid of a torch bulb or two.



The PP seems unaware of retarded potentials, and has blustered his way
by responding to the question without actually any understanding of
the issues involved.

On Sun, 14 Oct 2018 08:49:51 +0000, Spike
wrote:

On 13/10/2018 20:43, Jeff Liebermann wrote:

I understand how antenna work and how to predict performance. I can
even do it without 4NEC2 or other antenna modeling program. For
example, the uglier the antenna, the better it works. Antennas that
are more expensive, bigger, and in violation of local building
ordinances, work the best. Experimental prototype antennas always
work while the production versions never seem to work as well. If
there are two ways to assemble an antenna, the wrong way will have
higher gain, lower VSWR, or both. High gain, small size, or wide
bandwidth; pick any two. Using these rules of thumb and others,
anyone can predict how well an antenna will perform by inspection and
without using computer models, Smith charts, or tedious calculations.

WHS

Thou shalt not abrev. What does WHS mean?

There has been much talk on UKRA in the recent past about the merits or
otherwise of various makes and models of VNAs. It's my view that the
point of having an Amateur licence is to be able to transmit signals
intended to be received by another station. One of the alleged virtues
of a VNA is to be able to set up one's aerial system. However, I
maintain that using cheap torch bulbs is an equally valid indicator of
the state of tune of one's station, and that a distant station cannot
tell the difference between a system set up with the aid of a VNA and
one set up with the aid of a torch bulb or two.

In a past life (1970's), I used to design marine radios and antennas.
At the time, my weapon of choice was the HP4815A vector impedance
meter:
https://www.google.com/search?q=hp4815a&tbm=isch
No fancy display, no pretty graphs, no Smith chart display. Just
accurate numbers for the HF bands. I used it for everything that
needed impedance matching, including antennas. If you're thinking of
buying one, make sure that it includes the probe kit. It's useless
without the probe kit.
http://electropuces.pagesperso-orange.fr/Photos/HP4193.jpg

One of my ace technicians had a different way of doing RF. During the
day, he would use the best test equipment that the company could
afford. After hours, he would work on his own radios. However,
instead of using proper test equipment, he would literally tune for
maximum into a light bulb. I was disgusted, tried to help, but
failed. He insisted that a light bulb was "good enough". It took me
a while to decode what was happening.

Anyone can produce a workable antenna using primitive techniques. By
workable, I mean minimally functional and generally usable. For at
time, I was building matching networks for using an aluminum step
ladder as a VHF directional antenna. It worked, but improvements
beyond minimally functional were difficult.

So, why bother with all the fancy test equipment (VNA) if a light bulb
will do as well? Because with the fancy test equipment will squeeze
the last few decibels of performance out the antenna while the light
bulb is unlikely to do the same. If minimally acceptable is your
standard of excellence, then please continue using a light bulb for
tuning antennas. However, if you want to get all the performance
possible, then you'll need some fancy test equipment.

What was happening with my tech was that he did not want to expend the
time learning how to properly operate, understand, and analyze the
output from the fancy test equipment. While I consider this close to
sacrilege in a production environment, to someone just trying to get
his radio or antenna on the air, it's sufficient. If I light bulb got
him close enough to a working system, and didn't require any time to
study, it was "good enough".

Some of the local hams are very much into DX, contesting, and EME. To
be successful, one has to have a very efficient radio system with
everything optimized to the best possible performance. Everything has
to be optimized for the best possible performance. One can't do that
with a light bulb.

Since your view of ham radio is "to be able to transmit signals
intended to be received by another station", you don't need a VNA to
do that. An antenna tuner and a random length of wire will suffice.
However, if you plan to do more than that, some test equipment might
be useful.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann
wrote:
(...)
However, if you plan to do more than that, some test equipment might
be useful.

Since you prefer a minimalist approach to test equipment, as an
alternative to your light bulb, may I suggest a return loss bridge:
https://www.google.com/search?q=return+loss+bridge&tbm=isch
Note that there are several basic designs and configurations but all
are fairly simple and easy to construct. Note that these are NOT the
same as directional couplers.

You can purchase them on eBay:
https://www.ebay.com/sch/i.html?_nkw=return+loss+bridge

There are tutorials on YouTube:
https://www.youtube.com/results?search_query=return+loss+bridge

I have three of these made by Texscan:
https://www.qsl.net/n9zia/wireless/rtrn_loss-pics.html
https://www.qsl.net/n9zia/rlb/texscan.png

and a few that I've built for microwave frequencies:
http://pe2er.nl/wifiswr/

and one for HF:
http://www.dicks-website.eu/return%20loss%20bridge_part1/part1.html
http://www.dicks-website.eu/return%20loss%20bridge_part2/part2.html
http://www.dicks-website.eu/return%20loss%20bridge_part2/part3.html
http://www.dicks-website.eu/return%20loss%20bridge_part2/part4.html
http://www.dicks-website.eu/return%20loss%20bridge_part5/part5.html

A return loss bridge is similar to a VNA except that it does not
produce numbers for the real (resistive) and imaginary (reactive)
components of the antenna impedance. It just produces the return loss
compared to a reference termination resistor, which can then be
translated into the VSWR.

To use it, you need a minimum of an RF signal generator and a
voltmeter or oscilloscope. I prefer to sweep the frequency range of
interest, so I use an RF sweep generator, and display the result on an
oscilloscope. With this arrangement, you can tune your antenna
without requiring a light bulb.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 15/10/2018 01:20, Jeff Liebermann wrote:
On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann
wrote:

Since you prefer a minimalist approach to test equipment, as an
alternative to your light bulb, may I suggest a return loss bridge:
https://www.google.com/search?q=return+loss+bridge&tbm=isch
Note that there are several basic designs and configurations but all
are fairly simple and easy to construct. Note that these are NOT the
same as directional couplers.

To use it, you need a minimum of an RF signal generator and a
voltmeter or oscilloscope. I prefer to sweep the frequency range of
interest, so I use an RF sweep generator, and display the result on an
oscilloscope. With this arrangement, you can tune your antenna
without requiring a light bulb.

So, let me get this right. By employing a return-loss bridge, an RF
signal generator, and either a voltmeter or an oscilloscope, you can get
results that a distant station can't distinguish from those obtained by
using a torch bulb?

Given your ability to estimate the performance of an antenna by looking
at it rather than employ modelling methods, I would have though you
would be sympathetic to the merits of the torch bulb approach.


--
Spike

"Nearly all men can stand adversity,
but if you want to test a man's character,
give him an internet group to manage"

On Mon, 15 Oct 2018 12:16:14 +0000, Spike
wrote:

On 15/10/2018 01:20, Jeff Liebermann wrote:
On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann
wrote:

Since you prefer a minimalist approach to test equipment, as an
alternative to your light bulb, may I suggest a return loss bridge:
https://www.google.com/search?q=return+loss+bridge&tbm=isch
Note that there are several basic designs and configurations but all
are fairly simple and easy to construct. Note that these are NOT the
same as directional couplers.

To use it, you need a minimum of an RF signal generator and a
voltmeter or oscilloscope. I prefer to sweep the frequency range of
interest, so I use an RF sweep generator, and display the result on an
oscilloscope. With this arrangement, you can tune your antenna
without requiring a light bulb.

So, let me get this right. By employing a return-loss bridge, an RF
signal generator, and either a voltmeter or an oscilloscope, you can get
results that a distant station can't distinguish from those obtained by
using a torch bulb?

No. Per my previous rant, if your intent is "to be able to transmit
signals intended to be received by another station", then a light bulb
will suffice at producing the desired result. If your intent is to
design the best possible antenna, then you'll need something better.
If you just want to talk to someone, almost any kind of RF metering
device is sufficient.

There have been plenty of accounts of comparing various types of
antennas. For example, PSK Reporter is a good way to perform such a
test, where one can actually see the effects of antenna changes.
https://pskreporter.info/pskmap.html
What I've found is that such side by side comparisons do not account
for variations in propagation, path, interference, local noise, time
of day, position of the moon, and other factors beyond the operators
control. A given antenna might be far superior under one set of
condition, and rather disgusting under another. Most signal reports
also tend to be very subjective, inaccurate, and not repeatable.

If you are using a light built to tune a commercial antenna, which has
already been optimized in extensive lab and field tests, I suspect
that it is likely that a light bulb will give a similar result a
proper VSWR measuring device. (Actually, that's not quite correct
because I don't tune my antennas for minimum VSWR). However, that's
not why someone purchases and uses a VNA or swept return loss bridge.
They use these because they're building their own antenna, or
optimizing a commercial antenna. Once the antenna has been properly
tuned and tweaked, the VNA and return loss bridge are no longer needed
unless something changes.

Incidentally, I use a remote field strength meter to compare antennas.
It has it's limitations, but it's better than using VSWR or maximum
antenna current as in your light bulb method.

Given your ability to estimate the performance of an antenna by looking
at it rather than employ modelling methods, I would have though you
would be sympathetic to the merits of the torch bulb approach.

Since you seem impressed with my powers of observation, it might be
useful to know that to the best of my limited knowledge, light bulbs
went out of fashion in the 1930's, to be replaced by thermocouple
antenna current meters.
https://www.google.com/search?q=thermocouple+rf+ammeter&tbm=isch
It is much easier to see changes in a meter deflection than changes in
light bulb intensity, unless you also use a light meter. If you
select different light bulbs for different power levels, you might be
able to keep the losses to a minimum.

In any case, a VNA or even a return loss bridge is not for you. There
are plenty of things one can do with ham radio including "to be able
to transmit signals intended to be received by another station". You
seem intent on using the oldest and most crude methods of
accomplishing this. That's fine as there is room for retro-radio,
antique radio techniques, and preserving historical technology. I
would guess(tm) that your radios all use tube (thermionic valves) and
that you tune the transmitter for maximum cherry red glow in the
finals. Best of luck, but that's not for me.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 15/10/2018 16:45, Jeff Liebermann wrote:
On Mon, 15 Oct 2018 12:16:14 +0000, Spike
wrote:

On 15/10/2018 01:20, Jeff Liebermann wrote:
On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann
wrote:

Since you prefer a minimalist approach to test equipment, as an
alternative to your light bulb, may I suggest a return loss bridge:
https://www.google.com/search?q=return+loss+bridge&tbm=isch
Note that there are several basic designs and configurations but all
are fairly simple and easy to construct. Note that these are NOT the
same as directional couplers.

To use it, you need a minimum of an RF signal generator and a
voltmeter or oscilloscope. I prefer to sweep the frequency range of
interest, so I use an RF sweep generator, and display the result on an
oscilloscope. With this arrangement, you can tune your antenna
without requiring a light bulb.

So, let me get this right. By employing a return-loss bridge, an RF
signal generator, and either a voltmeter or an oscilloscope, you can get
results that a distant station can't distinguish from those obtained by
using a torch bulb?

No. Per my previous rant, if your intent is "to be able to transmit
signals intended to be received by another station", then a light bulb
will suffice at producing the desired result. If your intent is to
design the best possible antenna, then you'll need something better.
If you just want to talk to someone, almost any kind of RF metering
device is sufficient.

There have been plenty of accounts of comparing various types of
antennas. For example, PSK Reporter is a good way to perform such a
test, where one can actually see the effects of antenna changes.
https://pskreporter.info/pskmap.html
What I've found is that such side by side comparisons do not account
for variations in propagation, path, interference, local noise, time
of day, position of the moon, and other factors beyond the operators
control. A given antenna might be far superior under one set of
condition, and rather disgusting under another. Most signal reports
also tend to be very subjective, inaccurate, and not repeatable.

If you are using a light built to tune a commercial antenna, which has
already been optimized in extensive lab and field tests, I suspect
that it is likely that a light bulb will give a similar result a
proper VSWR measuring device. (Actually, that's not quite correct
because I don't tune my antennas for minimum VSWR). However, that's
not why someone purchases and uses a VNA or swept return loss bridge.
They use these because they're building their own antenna, or
optimizing a commercial antenna. Once the antenna has been properly
tuned and tweaked, the VNA and return loss bridge are no longer needed
unless something changes.

Incidentally, I use a remote field strength meter to compare antennas.
It has it's limitations, but it's better than using VSWR or maximum
antenna current as in your light bulb method.

Given your ability to estimate the performance of an antenna by looking
at it rather than employ modelling methods, I would have though you
would be sympathetic to the merits of the torch bulb approach.

Since you seem impressed with my powers of observation, it might be
useful to know that to the best of my limited knowledge, light bulbs
went out of fashion in the 1930's, to be replaced by thermocouple
antenna current meters.
https://www.google.com/search?q=thermocouple+rf+ammeter&tbm=isch
It is much easier to see changes in a meter deflection than changes in
light bulb intensity, unless you also use a light meter. If you
select different light bulbs for different power levels, you might be
able to keep the losses to a minimum.

In any case, a VNA or even a return loss bridge is not for you. There
are plenty of things one can do with ham radio including "to be able
to transmit signals intended to be received by another station". You
seem intent on using the oldest and most crude methods of
accomplishing this. That's fine as there is room for retro-radio,
antique radio techniques, and preserving historical technology. I
would guess(tm) that your radios all use tube (thermionic valves) and
that you tune the transmitter for maximum cherry red glow in the
finals. Best of luck, but that's not for me.

Very interesting, but I'd have to say that none of what you say refutes
my original contention that the distant station, which after all is the
one we are trying to communicate with, will notice any difference to the
received signal whether the sending station's antenna was tuned with a
20c torch bulb or a $300 VNA. You touched on the main vagaries of the
system when you said "What I've found is that such side by side
comparisons do not account for variations in propagation, path,
interference, local noise, time of day, position of the moon, and other
factors beyond the operators control".


--
Spike

"Nearly all men can stand adversity,
but if you want to test a man's character,
give him an internet group to manage"

Spike wrote:
On 15/10/2018 16:45, Jeff Liebermann wrote:
On Mon, 15 Oct 2018 12:16:14 +0000, Spike
wrote:

On 15/10/2018 01:20, Jeff Liebermann wrote:
On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann
wrote:

Since you prefer a minimalist approach to test equipment, as an
alternative to your light bulb, may I suggest a return loss bridge:
https://www.google.com/search?q=return+loss+bridge&tbm=isch
Note that there are several basic designs and configurations but all
are fairly simple and easy to construct. Note that these are NOT the
same as directional couplers.

To use it, you need a minimum of an RF signal generator and a
voltmeter or oscilloscope. I prefer to sweep the frequency range of
interest, so I use an RF sweep generator, and display the result on an
oscilloscope. With this arrangement, you can tune your antenna
without requiring a light bulb.

So, let me get this right. By employing a return-loss bridge, an RF
signal generator, and either a voltmeter or an oscilloscope, you can get
results that a distant station can't distinguish from those obtained by
using a torch bulb?

No. Per my previous rant, if your intent is "to be able to transmit
signals intended to be received by another station", then a light bulb
will suffice at producing the desired result. If your intent is to
design the best possible antenna, then you'll need something better.
If you just want to talk to someone, almost any kind of RF metering
device is sufficient.

There have been plenty of accounts of comparing various types of
antennas. For example, PSK Reporter is a good way to perform such a
test, where one can actually see the effects of antenna changes.
https://pskreporter.info/pskmap.html
What I've found is that such side by side comparisons do not account
for variations in propagation, path, interference, local noise, time
of day, position of the moon, and other factors beyond the operators
control. A given antenna might be far superior under one set of
condition, and rather disgusting under another. Most signal reports
also tend to be very subjective, inaccurate, and not repeatable.

If you are using a light built to tune a commercial antenna, which has
already been optimized in extensive lab and field tests, I suspect
that it is likely that a light bulb will give a similar result a
proper VSWR measuring device. (Actually, that's not quite correct
because I don't tune my antennas for minimum VSWR). However, that's
not why someone purchases and uses a VNA or swept return loss bridge.
They use these because they're building their own antenna, or
optimizing a commercial antenna. Once the antenna has been properly
tuned and tweaked, the VNA and return loss bridge are no longer needed
unless something changes.

Incidentally, I use a remote field strength meter to compare antennas.
It has it's limitations, but it's better than using VSWR or maximum
antenna current as in your light bulb method.

Given your ability to estimate the performance of an antenna by looking
at it rather than employ modelling methods, I would have though you
would be sympathetic to the merits of the torch bulb approach.

Since you seem impressed with my powers of observation, it might be
useful to know that to the best of my limited knowledge, light bulbs
went out of fashion in the 1930's, to be replaced by thermocouple
antenna current meters.
https://www.google.com/search?q=thermocouple+rf+ammeter&tbm=isch
It is much easier to see changes in a meter deflection than changes in
light bulb intensity, unless you also use a light meter. If you
select different light bulbs for different power levels, you might be
able to keep the losses to a minimum.

In any case, a VNA or even a return loss bridge is not for you. There
are plenty of things one can do with ham radio including "to be able
to transmit signals intended to be received by another station". You
seem intent on using the oldest and most crude methods of
accomplishing this. That's fine as there is room for retro-radio,
antique radio techniques, and preserving historical technology. I
would guess(tm) that your radios all use tube (thermionic valves) and
that you tune the transmitter for maximum cherry red glow in the
finals. Best of luck, but that's not for me.

Very interesting, but I'd have to say that none of what you say refutes
my original contention that the distant station, which after all is the
one we are trying to communicate with, will notice any difference to the
received signal whether the sending station's antenna was tuned with a
20c torch bulb or a $300 VNA. You touched on the main vagaries of the
system when you said "What I've found is that such side by side
comparisons do not account for variations in propagation, path,
interference, local noise, time of day, position of the moon, and other
factors beyond the operators control".


#Waves

--
STC / M0TEY /
http://twitter.com/ukradioamateur

In article , lid
says...

Very interesting, but I'd have to say that none of what you say refutes
my original contention that the distant station, which after all is the
one we are trying to communicate with, will notice any difference to the
received signal whether the sending station's antenna was tuned with a
20c torch bulb or a $300 VNA. You touched on the main vagaries of the
system when you said "What I've found is that such side by side
comparisons do not account for variations in propagation, path,
interference, local noise, time of day, position of the moon, and other
factors beyond the operators control".




Sometimes it is who is doing the adjusting and not how good the
equipment is.

Almost 40 years ago I started keeping a repeater on the air that was
started by someone else. My test equipment at that time was a VTVM, a
$ 25 Heathkit signal generator, old Oscilloscope, swr meter, and
frequency counter.

To tune the receiver my best 'signal generator' was a ham near the edge
of the repeater coverage. I would have him just to key down for a
minuit or two at a time while I adjusted the receiver. Over the years a
better receiver and transmitter was installed. Now I have some very
good test equipment, but can not say the coverage of the repeater is
very much better. What little improvement is made is probably because
the radio equipment is better.

At that time one thing I did not try to adjust or check was the duplexer
as I did not think I could with what I had to work with. Many years ago
the tuning instructions for duplexers was to tune for maximum signal on
the pass and best rejection. As test equipment became better and priced
in range, the pass tuning changet to using a return loss bridge and
SA/TG. This seems to work much better. I found the pass was broad and
you could usually give the tuning rod a turn or two without much effect,
but he RLB shows up in less than 1/2 of a turn. Does it make a
difference ? Probably not in effective coverage (it may extend the
range a foot or two,hi), but atleast I know it tuned the best it can be
with what I have to work with.

One thing that does come with better test equipment is knowing that the
equipment is tuned so it meets or exceeds the specificatioins. Before
it was just a guess as if the equipment did or did not meet
specifications.

On Tue, 16 Oct 2018 07:44:53 +0000, Spike
wrote:

Very interesting, but I'd have to say that none of what you say refutes
my original contention that the distant station, which after all is the
one we are trying to communicate with, will notice any difference to the
received signal whether the sending station's antenna was tuned with a
20c torch bulb or a $300 VNA. You touched on the main vagaries of the
system when you said "What I've found is that such side by side
comparisons do not account for variations in propagation, path,
interference, local noise, time of day, position of the moon, and other
factors beyond the operators control".

Perhaps an analogy might be useful. Instead of an HF radio, you're
dealing with your automobile. Under normal circumstances, it will get
you to work and back fairly efficiently. However, you notice that
your gasoline (petrol) mileage is not quite what you might expect. So,
you have a choice of mechanics. The first mechanic tunes the engine
with a light bulb, divining rod, magic incantations, and offers a
rather bizarre description of what work was done on the vehicle. The
second mechanic uses proper computerized test equipment to analyze the
situation, uses factory parts, and delivers the car with a detailed
printout of what was done, what changes were made, what parts were
used, and a before-after gas mileage comparison performed on a
dynamometer.

Now, which mechanic would you prefer? Your car will still go to work
and back in some manner. The second mechanic will cost more, because
he has to pay for all the expensive equipment and genuine parts. If
you're impoverished, obviously the first mechanic will be the only
available choice, but assuming you plan to keep the vehicle, one might
suspect it is a bad long term solution.

From my perspective, both professional and as a ham, I deal in
numbers. I can tell by looking at the numbers what is happening and
what needs to be done. I have a small collection of aging test
equipment to help me generate the numbers. Light bulbs do not
generate numbers and are therefore (in my never humble opinion)
useless and worthless.

However, I will concede that if your intent is "to be able to transmit
signals intended to be received by another station", a light bulb is
sufficient to determine that your transmitter is spewing RF, spurs,
harmonics, and noise into an antenna-like device that is either
radiating the RF, absorbing it into heat, or reflecting it back to the
transmitter (because the light bulb indicates the same in both
directions).



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558