I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that
mean? And so you see a huge difference in the stock stabilizer?

Thank You

On Mon, 06 Sep 2004 14:00:42 -0700, johnnyjumpup wrote:

I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that mean?
And so you see a huge difference in the stock stabilizer?

You really don't need this unless you are receiving digital modes. And at
that, unless the room you are in drastically changes temperature or the
12v supply changes voltage, you don't need the stability. However, there
are some people who feel better having it.

johnnyjumpup wrote:

I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that
mean? And so you see a huge difference in the stock stabilizer?

A crystal is used to set the frequency in the radio. Crystals will
change frequency a bit with changing temperatures This is called 'drift'.

To prevent this, a really accurate crystal will be held at an even
temperature by some sort of heating device. The temperature of this has
to be above any normally encountered room temperature...for obvious reasons.

It's easier to vary the heat to the crystal than to adjust the frequency
by other means. It may be a nice thing to have, but most likely
unnecessary. It may be good if you were taping all night and didn't want
the station *maybe* slowly fading out due to frequency shift.


The worst radio I've ever seen for this was a cheap 35 dollar Grundig(1)
multiband. It would change 10 kilohertz in under three hours. A related
problem is it's inability to keep time. Garbage.



(1) a once respected name

mike

m II wrote:

johnnyjumpup wrote:

I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that
mean? And so you see a huge difference in the stock stabilizer?

A crystal is used to set the frequency in the radio. Crystals will
change frequency a bit with changing temperatures This is called 'drift'.

To prevent this, a really accurate crystal will be held at an even
temperature by some sort of heating device. The temperature of this has
to be above any normally encountered room temperature...for obvious reasons.

It's easier to vary the heat to the crystal than to adjust the frequency
by other means. It may be a nice thing to have, but most likely
unnecessary. It may be good if you were taping all night and didn't want
the station *maybe* slowly fading out due to frequency shift.

The worst radio I've ever seen for this was a cheap 35 dollar Grundig(1)
multiband. It would change 10 kilohertz in under three hours. A related
problem is it's inability to keep time. Garbage.

(1) a once respected name

What the hell did you expect for $35?

dxAce

There are quite a few inexpensive electronic gems out there, innate! Especially
in the used marts; although yer gratuitous grumpiness would probably doubt
their existence! That sweetly singin' Rotel RX-602, here in the computer room,
wuz a mere $14 fer 35 watts-per-channel of direct-coupled harmonic heaven &
killer f.m. section! Me beloved Marantz MR-235, with 35 w.p.c. of valvesque
lateral-mosfet direct-coupled mini-Marshall vibe, wuz all of $28!
Cap-n-resistor mods added another $20 to da tab! ... As previously stated,
johannjumpup, unless yer QTH suffers from temperature extremes, ya won't need
that TCXO-4 frequency stablizer. Get thyself that f.m. module instead, & pray
for good propogation on 29.5 mhz! Your Century Frog was based on the receiver
section of Yaesu's FT-890 transceiver, & seems bereft of the problems plaguing
aging FRG-7000s, FRG-7700s, & FRG-8800s! All the best from Sactown for good
dx!!!

dxAce wrote:


What the hell did you expect for $35?

A lot more change than they gave me.

In all fairness the thing works ok within it's economic constraints(1).
I believe this model is the one they were giving away free if you bought
a Satellit 800 or somesuch.


(1) political buzzword for the day)


mike



(I didn't feel like typing in my normal signature this time)

It will stabilize the oscillator. The real question is whether it is
needed. It could be useful if you are going to park on one frequency
and the receiver has to stay on frequency for a long time. As you
might find when receiving a multiplex signal. For most modern
receivers drift isn't a real problem.



(johnnyjumpup) wrote in message . com...
I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that
mean? And so you see a huge difference in the stock stabilizer?

Thank You

On 6 Sep 2004 14:00:42 -0700, (johnnyjumpup)
wrote:

I have aquired an FRG-100, and am curious as to wha the option TCXO-4
does, I know that it stabilizes the frequency, but what does that
mean? And so you see a huge difference in the stock stabilizer?

Thank You

TCXO = Temperature Compensated Crystal Oscillator

It is common shorthand to refer to "crystal" as "xtal" or simply "X"
when used in an acronym.
The device will (usually) operate the xtal element at an elevated
temperature, say 100 degrees F or so, plus or minus a few tenths of a
degree. This stabilizes the crystal frequency to a feww ppm or less.

cheers