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Here's the straight skinny on a cap hat addition: It'll do more for
tuning just above the coil, because it's closer to ground, but it'll
add more to the signal at the tip. Closer to ground, it has more
capacitance, but current that flows into its capacitance will not flow
int the vertical part of the antenna above the coil, so even if you
can TUNE, you may not have as good a signal as you could. If the added
capacitance hat is at the top, then the current that flows in its
capacitance will also flow through the radiation resistance (small as
it may be) of the vertical part above the coil, and help your signal.

(Additionally, a cap hat just above the coil makes more current flow
in the coil turns, which are pretty lossy, compared to putting it
higher.)

And when ten meters is open... where's that noodle soup? I gotta try a
wet noodle!

Cortland

--- In FT817@e..., "Richard B Drake" <rich@w...> wrote:

Oh, I clipped at the tip of the whip, a capacity hat. Are you saying

it will

have a greater affect if it's just above the coil? Well, what the

heck, I'll

try it, it's just a matter of moving a clip :-)

-----
73, Rich - W3ZJ
www.w3zj.com

--- In FT817@y..., harry.edwards@s... wrote:

I have been hearing some rumors from some Hams in "VK Land" about

the

ability to increase the output of the 817 through a "hidden" menu.

Anyone heard anything else about this. I'll be on a "QRP

Dxpedition"

in a few months and a few more watts would be nice.

Thanks in advance for any thoughts on this.

:harry edwards
W6DXO

Hi Harry,

Best not to increase the power beyond the specified level to maintain
the life cycle of the rig. If you are going to operate SSB, then get
the optional SSB filter and realize a couple of dB gain, use the Heil
HC-4 or HC-5 element in your mic and get a bit more punch, and
carefully adjust the 817 for your voice to achieve the greatest talk
power and clarity.

You didn't say what type of DXpedition you plan, but the number one
ingredient to success (after the bands being open of course) is
having a really good antenna system. A little whip just doesn't cut
it.

Gl es 72 de Barry - W4WB

Oh, I clipped at the tip of the whip, a capacity hat. Are you saying it will
have a greater affect if it's just above the coil? Well, what the heck, I'll
try it, it's just a matter of moving a clip :-)

-----
73, Rich - W3ZJ
www.w3zj.com

Duh, guess I got it wrong, I thought we were suppose to reduce power, 5
watts is overkill now!
--
Rich Clemens
clemens@...

The information on the hidden menu is in the FAQ on yahoogroups.com. But if
you are looking to destroy your radio or at the very least shorten it's life
for the sake of an imperceptible gain in signal strength, my advice is,
"DON'T DO IT"

-----
73, Rich - W3ZJ
www.w3zj.com

If set up as specified in the service manual, the radio considers the
radio to be "off frequency" (in the non-FMN mode, anyway) when >3-3.5
KHz off-center.

This "tuning" status is obtainable using the 0xE7 "Read Receiver
Status" CAT command by looking at bit 5 (when bit 0 is the LSB.) I
haven't found a way to "look" at the discriminator output in a way
other than the "on-off" indication that the bit offers.

I would suspect that if the scanning is done in >= 5 KHz steps, it
should always land in the center - assuming that the signal being
received is on a frequency that is on a 5 KHz interval, for example.
Now, if there isn't any "averaging" done in hardware or software, then
it is possible that incidental modulation can cause the '817 to
"catch" a signal as it is "off frequency" during modulation peaks:
This would be something to check out.

--- In FT817@y..., "Pres Waterman" <pres@1...> wrote:

I was just perusing my new service manual ( yay! ) > GO BILLS!

Hey Pres, Do you have the "new" service manual? If so, it would be
interesting to put together a "diff" sheet showing how the two manuals
differ in their procedures. (Some of those in the original manual are
just plain wrong - guaranteed to "un-spec" a radio if followed to the
letter...)

Clint
KA7OEI

I would suspect that if the scanning is done in >= 5 KHz steps, it
should always land in the center - assuming that the signal being
received is on a frequency that is on a 5 KHz interval, for example.

I agree... IF the radio is set up to care. Most radios only look for squelch
opening.

Now, if there isn't any "averaging" done in hardware or software, then
it is possible that incidental modulation can cause the '817 to
"catch" a signal as it is "off frequency" during modulation peaks:
This would be something to check out.

--- In FT817@y..., "Pres Waterman" <pres@1...> wrote:

I was just perusing my new service manual ( yay! ) > GO BILLS!

Hey Pres, Do you have the "new" service manual? If so, it would be
interesting to put together a "diff" sheet showing how the two manuals
differ in their procedures. (Some of those in the original manual are
just plain wrong - guaranteed to "un-spec" a radio if followed to the
letter...)

I dunno... how would I tell the vintage of the manual?

Pres Waterman W2PW
c/o Patchogue Motors, Inc.
Long Island Ford and Kia dealer

GO BILLS!

Pres wrote:

Seems there is a FM discriminator center alignment.

I believe this simply refers to alignment of the frequency to voltage
conversion curve placement within the IF post-filter passband.

The "FM discriminator center" usually refers to a voltage/frequency
point about halfway between both PLL lock frequencies in an FM PLL's
Z-curve (or midway within the linear part of an FM discriminator's
S-curve).

Alignment of the discriminator center should match the center of the
last IF passband filter (which varies slightly from filter to filter).
Alignment is usually made easy by simply using an IF frequency sweep
oscillator at low amplitude, injected pre-filter in the IF, an
oscilloscope with horizontal scale driven from the sweep oscillator
sawtooth output, and the vertical scale driven by a probe at the
direct output of the FM demodulator.

Bonnie KQ6XA

Rich - did you clip at just above the coil or at the tip of the whip? A
shorter length should work just over the coil, or better, zo's round hat just
over the coil. Good luck in any event.

HI Gang,

I have purchased Inrad(Collins) CW filter and the
expirimenters Collins SSB filter from Inrad. The SSb
filter is the same one for the 817 with out the PC
board. If the ceramic filter is removed and pins
installed in its place and a new circuit board is
designed that will hold both filter then yes they will
fit. I have set the SSB filter next to the CW
filter(between filter and housing) in the radio and
there is room for a larger circuit board. This is what
I intended for the extra filter:-) This project will
have to wait a while because of work demands(not even
enought time to stop and tie my shoes it seems some
days).

73, Skip NC9O

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I have been hearing some rumors from some Hams in "VK Land" about the
ability to increase the output of the 817 through a "hidden" menu.

Anyone heard anything else about this. I'll be on a "QRP Dxpedition"
in a few months and a few more watts would be nice.

Thanks in advance for any thoughts on this.

:harry edwards
W6DXO

Those who use 2m FM ( I don't ) may want to check and report if
scanning in 5KHz steps results in a correct stop, not too early. I
think mine does if I recall.

Hi Pres,
My '817 will stop 5KHz off-center every time, if the signal is good &
strong. A'course, I need to send it in for birdies & noise blanker
work anyway, so I guess I'll mention this as well!

Yea - that is curious isn't it - - I suspect that it is the same
syndrome that is affecting lots of engineers these days - engineering
to the edge of the envelope and not allowing for any slop - i.e.:if
the circut is @ 16v, then a capacitator rated at 16 v should do
it.... wrong..... I have discussed this with folks I know that work
in the tech engineering field that head engineering teams, and they
confirm this..... It drives me (& them) nuts to see that the most
common failure in a piece of equipment is in the power supply -
something that is relativly easy to engineer.

I don't have quite this bad a problem with the Maldol - I think mine
actually might be ok - but I do with the ATX, and cured it by making
a 4 spoke capacity hat out of 24 gauge solid wire and soldering it to
a mini-aligator clip.

Don
W6ZO


--- In FT817@y..., "Richard B Drake" <rich@w...> wrote:

The curious thing about that is you would think that they would

design them

to be a little low in frequency so that all you would have to do is

push the

whip in a little to get it where you want it. But they make it high

where

you can't do a darned thing about it other than add an external

loading

device, or kludge up some kind of whip extension.

-----
73, Rich - W3ZJ
www.w3zj.com


-----Original Message-----
From: tar@p... [mailto:tar@p...]
Sent: Wednesday, June 20, 2001 7:29 PM
To: FT817@y...
Subject: [FT817] Re: MALDOL whip - SWR kinda crummy?


Kinda is not even close.

I tested some Maldol whips with an MFJ259B. At that time the 40,

20

and 10 meter versions were available from my local radio dealer.

The 10m is fine, and resonates at a little less than 29meg.

The 20m will not go under 16.5 mhz even with a counterpoise.

The 40m is similarly high.

The resonant points had reasonable SWRs, just too high in

frequency in

the 40 and 20 cases.

I don't know how any of the other available bands work other than

the

3 I tested.

If someone could find a way to extend the whip a couple feet in a

way

that would be strong and light, they might work OK.

tom
wa2phw

--- In FT817@y..., "Richard B Drake" <rich@w...> wrote:
> Nope, with the 20 meter Maldol mounted directly on the FT-817,

I get

4 to 5
> bars in on the SWR display and have been completely unable to

adjust

that or
> make a contact with it. Mounting it on the Z11 tuner will give

you a

perfect
> match and then it also works!



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Service.

I was just perusing my new service manual ( yay! ) and looked into the
alignment menu. Seems there is a FM discriminator center alignment. Now, I
don't recall any zero-center display so this leads me to believe there is a
scan stop parameter that depends on being ON channel. Very nice feature.

Those who use 2m FM ( I don't ) may want to check and report if scanning in
5KHz steps results in a correct stop, not too early. I think mine does if I
recall.

Thanks

Pres Waterman W2PW
c/o Patchogue Motors, Inc.
Long Island Ford and Kia dealer

GO BILLS!

The '817 doesn't consider the SWR to be "high" until it is over 3 or
so bars - but that doesn't mean that it won't cut the power back
before then.

What would be interesting to find out is if the '817 actually detects
the SWR (that is, takes both the forward and reflected power into
accoutn) and acts on that, or simply reduces power to limit reflected
power to an absolute amount regardless of foward power. This would be
easy to verify by deliberately mismatching the radio's termination
(resistively, of course) and changing the power levels - but I haven't
done it.

The '817 uses three bridges to determine forward and reflected power
on the various bands. On HF/6M it uses a "monimatch" type of bridge -
essentially where the RF goes through the center of a toroid and the
forward and reverse power is detected from the secondary. On VHF and
UHF, two seperate "stripline-type" detectors are used. The former has
the advantage of easily being broadbanded over more than a decade of
frequency with consistent reading, where the latter type are
inherently narrowbanded (coupling increasing with frequency.)

Neither type by themselves are able to properly determine the "true"
VSWR (i.e. a circle on a smith chart) but they will certainly detect a
gross mismatch and do their intended job of protecting a radio.

After I got my '817, I noticed that on HF, a 50 ohm resistive load
showed no bars on reflected power. On 6 meters, this wasn't the case
- so I went through the alignment procedure again, this time using 6
meters instead of 10 meters as the procedure recommended, with the
result being that 6 meters was correct- but HF was wrong. Noticing
that there seemed to be a "range" over which the trimmer cap could be
adjusted with a "zero" reading on any particular band. After a bit of
experimentation, I found a setting that resulted in a reading of zero
on HF-6 meters.

Note: This information is documented at:


Obviously, they aren't going to go through this much trouble at the
factory - nor should they be expected to. But, if you have the skill
and equipment to do so - and your '817 exhibits this behavior (*AND*
it bothers you...) then you now know what to expect.

A word of warning here: Because all meters are different - don't
believe that the VSWR *really* is 1:1 just because the meter says so:
Unless you had a full-blown impedance bridge inline, there could be
any number of resistance-reactance combinations that can cause a false
indication of a perfect match. The only way to be sure of a good
match to the radio itself is to put a 50 ohm resistive termination
directly on the radio's antenna terminal.

Clint
KA7OEI

--- In FT817@y..., patrickdonohue@h... wrote:

Will this damage the battery?

I've posed this question to the manufacturer and there has been no
response to date....

73s

Patrick E. Donohue
KG4NYO

I have used a 7 amp gel cell in auto cig plug and no damage to
battery, but I only did this with one that is charged. I would NOT
plug up my discharge 7 amp gel cell in cig plug.

Also I would not leave it plugged up on extended trips if auto
voltage exceeds 14 volts. But I have used gel cell connected to rig
& used car to keep battery charged. By running rig off gel cell in
car you will help keep some noise out of radio & for larger power
output rigs less strain on the electrical system.

Its always best to run rig staight off of car battery, but in some
cases this is not possible. My company forbids it in their company
cars.

Hope this helps,
Reed W4JZ

Question: What if you added a solid rod about 12 inches long on top of the coil, then put the whip on top of that. Aluminum rods are cheap and should be able to find one the right size. Then just drill and tap each end as needed.

Stephen Souza
ssouza@...

All in product marketing I would guess.

The longer the whip, the larger the base diameter must be, right? And
a larger base might not fit on the rig's BNC because it would bump
against the SEL knob.

I bet Maldol opted for what they could sell vs. what performs best.
Because the same whip is used for all of the coils, Maldol had to
create a "one size fits all" whip. And since the instructions that
come with the whip state that adding a counterpoise is best for
optimum performance, they more or less concede the fact that the whip
is a bit too short for certain bands.

That's OK though. Not a big deal to cut a piece of wire to
assure "optimum performance." Even if the thing were flat without
the added counterpoise I would only expect from it what it
represents - a small whip on a low power rig with zero gain. It's
still fun to play with.

Jason - NF6E

--- In FT817@y..., "Richard B Drake" <rich@w...> wrote:

The curious thing about that is you would think that they would

design them

to be a little low in frequency so that all you would have to do is

push the

whip in a little to get it where you want it. But they make it high

where

you can't do a darned thing about it other than add an external

loading

device, or kludge up some kind of whip extension.

-----
73, Rich - W3ZJ
www.w3zj.com


-----Original Message-----
From: tar@p... [mailto:tar@p...]
Sent: Wednesday, June 20, 2001 7:29 PM
To: FT817@y...
Subject: [FT817] Re: MALDOL whip - SWR kinda crummy?


Kinda is not even close.

I tested some Maldol whips with an MFJ259B. At that time the 40,

20

and 10 meter versions were available from my local radio dealer.

The 10m is fine, and resonates at a little less than 29meg.

The 20m will not go under 16.5 mhz even with a counterpoise.

The 40m is similarly high.

The resonant points had reasonable SWRs, just too high in

frequency in

the 40 and 20 cases.

I don't know how any of the other available bands work other than

the

3 I tested.

If someone could find a way to extend the whip a couple feet in a

way

that would be strong and light, they might work OK.

tom
wa2phw

--- In FT817@y..., "Richard B Drake" <rich@w...> wrote:
> Nope, with the 20 meter Maldol mounted directly on the FT-817,

I get

4 to 5
> bars in on the SWR display and have been completely unable to

adjust

that or
> make a contact with it. Mounting it on the Z11 tuner will give

you a

perfect
> match and then it also works!



Yahoo! Groups Sponsor



To unsubscribe from this group, send an email to:
FT817-unsubscribe@y... and for a great FAQ ( Frequently Asked
Questions ) see
Please note that your messages and files sent to this group

become public

domain upon submission and may appear anywhere on the Internet or

in print

without notice or compensation.



Your use of Yahoo! Groups is subject to the Yahoo! Terms of

Service.

--- In FT817@y..., mike newbold <mt_top@y...> wrote:

I bet by now, a lot of you are NOT using the AA
Battery compartment. what a great place to install a
DSP unit( amongst other things). any one done that or
working on one?

817- one of my favorite radios
tnx 73
mike K0YO

Hi Mike,

I have an Amcom Base DSP Unit, I opened it up to look at the board.
It looks like it would fit in the area where the battery pack fits.
Unfortunately due to work commitments,
I'm not in a position to do any serious work on this at present.

Rgds
David

Don't connect the gel cell directly to the cigarette lighter plug
without some current limiting! You could blow up the gel cell!!

Phil - AD5X

--- In FT817@y..., patrickdonohue@h... wrote:

After going through far too many AA Duracells, I have broken down

and

purchased what was called a Power Kit from www.PowerPortStore.com
(those folks who make the WorldPouch etc.) which is a 12 volt 2.3

amp

gel cel battery. As quickly as the Duracells were draining I found

it

useful to attach a Cigarette lighter plug to the power cable that
came with my 817 so that I could use it in my vehicle as well as
utilize an AC power supply I have at home.

Anyway, I would like to attach that Cig Plug to the leads that come
off of the gel cel. that would enable me to use auto/ac-converted
power when available (perhaps even slow charge) and leave me
connected and using battery when it's not available (just need to
roll up and stash the cord...)

Will this damage the battery?

I've posed this question to the manufacturer and there has been no
response to date....

73s

Patrick E. Donohue
KG4NYO