Date   

PTT with Berhinger x802

mark <n8ibz@...>
 

I have tried to get the ic7000 to transmit using pin 4 and 7 though the rear mic connector with the pr781 connected to the 13pin acc port(2/11) but it will not go into transmit.

My question is with the Berhinger going to pins 2/11 can I use Pin 3 and pin 2 for the PTT on the 13 pin port?

Bob Heil suggested I use the rear mic connector but I can't get it to transmit(go to tx)using(4/7, with pin 4ptt and 7gnd), anyone use the this method and which pin# did you use????


73 Mark


uk emc power cable

Graham Saville <graham.saville@...>
 

Email sent on Tuesday 13/04/2010 at 16:27:19
Hi not sure if this has been discussed in the past but why does the ic7k that are sold in the uk have emc filters and the ones in the us don't? also does the filter stop rf getting into the radio?
73's Graham G1rnz


AH4 connector

Ronald Baran
 

Hi All,

I need to whip up a patch cable for an AH4. The back of the 7K has a connector on the back referred to as "tuner control socket". (Manual, page 11, #6) I should probably know this but what do you call that socket. If you were going to order a few of those - both male and female - what do you ask for?

Thanks,

Ron W9XS


Re: RTTY or CW to check SWR on 7000 I am having problems

Jack Rucker <jackr1@...>
 

Steve,

HV Mica caps can be found in WW2 surplus BC-375E. Be sure to get one with a complete set of tuning units.

They were easily found in 1948 for ~$15. Y$MV

Jack_son
=================================================

----- Original Message -----
From: Steve
To: ic7000@yahoogroups.com
Sent: Tuesday, April 13, 2010 12:45 AM
Subject: [IC-7000] Re: RTTY or CW to check SWR on 7000 I am having problems

Mac,
Do you remember the size and number of turns for the High Sierra HS-1500 coil?
Not easy to "find" higher voltag equality MICA caps.......

Regards.
Steve
AB2ET/4

- - - - S N I P - - - -


Re: RTTY or CW to check SWR on 7000 I am having problems

Steve Sawicki
 

Mac,
Do you remember the size and number of turns for the High Sierra HS-1500 coil?
Not easy to "find" higher voltag equality MICA caps.......

Regards.
Steve
AB2ET/4

--- In ic7000@yahoogroups.com, D C *Mac* Macdonald <k2gkk@...> wrote:


The matching device needed is simply a coil with the
proper inductance SHORTED from the feedpoint to the
chassis ground. This coil along with a small portion
of the loading coil of the antenna forms an "L" network
to match the very low impedance on 40 and even lower
on 75/80 meters to the 50 Ohm impedance of your coax.
It is virtually lossless.

A fixed capacitor at the same location will also serve
to get you a correct match. Try 1,000 or 470 pFd for
75/80 and 470 or 270 for 40. It's been so long that I
have forgotten the actual starting values. Use good
quality MICA caps, the higher voltage rating the better
(within reasonable phyisical size limits).

With the High Sierra HS-1500 (replaced by HS-1800)
one coil is used for all bands from 80M through 10M.

The old Master Mobile (60s and 70s) setup, there was
a manually variable inductor in the same location that
could be reset for each band. I still have that setup
(that I bought in 1962) out in the garage with lots of
other old stuff.

If you don't need help to match your antenna to 50
Ohm coax, you have an antenna that is excessively and
unnecessarily lossy!

73 - Mac, K2GKK/5
(Since 30 Nov 53)
Oklahoma City, OK


Re: IC-7000 50 watts on some bans?????

Steve W3AHL
 

What mode were you using for the testing? On 160m & 80m, what does the ALC indicator and the internal SWR meter show at 100% power? If the ALC has ALL of the right most red bars ON, then something is causing the APC to reduce the power. If the internal SWR is below 1.5, that isn't the problem. Based upon your voltage measurements the PA isn't drawing too much current, so that isn't the problem.

About the only thing that makes sense is there is a logic problem selecting the correct HP & LP filters for the lower bands.

Give Icom Service a call and see if they have any ideas. It probably needs to be returned.

Steve, W3AHL

--- In ic7000@yahoogroups.com, "BASILIE" <n8nqu@...> wrote:



Have you measured the TX power into a known good dummy load, bypassing the
tuner? It is unlikely this is a problem with the radio.
Yes,i went into a heath cantenna with no tuner inline and I did check the voltage on pin 3 and 4,I am using a VS-70amp Astron.Here is what I found.

160 meters
100% rf power 20 watts Idle 14.00 volts under load 13.61 volts
50% " " 2 watts " " 13.65 "

80 meters
100% 48 watts " " 13.37 "
50% 5 watts 13.62 "

40 meters
100% 50 watts 13.10 "
50% 8 watts 13.45


20 meters
100% 105 watts 13.29
50% 50 watts 13.05
10 meters 100 watts
100% 100 watts 13.00
50% 50 watts 13.32

I hope this makes sense.











--- In ic7000@yahoogroups.com, "Steve W3AHL" <w3ahl@> wrote:

Have you measured the TX power into a known good dummy load, bypassing the tuner? It is unlikely this is a problem with the radio.

Also, verify the DC voltage at the radio while transmitting at full power. The best place to measure it is on pins 3 & 4 of the antenna tuner connector. It should be 12.8-13.2 volts to get full power output.

More details on your test method would help.

Steve, W3AHL

--- In ic7000@yahoogroups.com, "BASILIE" <n8nqu@> wrote:

Does anybody know why 10-20 meters I have 100 watts and 40-160 meters only have 50 watts??????I am using the radio with the LDG IT-100.It's got me thinking that I have something major wrong with the radio.Serial Number is 05107xx.Thanks Bill N8NQU.73.........


Re: IC-7000 50 watts on some bans?????

scott_scheirman <ad7xv@...>
 

And I don't know what a *heath antenna* is, It sure sounds like it's an antenna and not
a dummy load
A Heath(kit) cantenna is a 50 ohm resistor in a gallon can (like a paint can) of oil. An SO239 connector is on the lid.

So yes, it is a dummy antenna.

Caveat: I've heard that some of the original oil from 20+ years ago may have contained PCBs, so one may want to think twice before purchasing a used one unless oil has never been installed.

Scott
AD7XV


Re: [IC-7000] Re: IC-7000 50 watts on some bans?????

Luis Saavedra
 

If there is power being reflected in the 160/80/40m cases your dummy load is not
presenting a 50-ohms resistive load to the RF output of your transceiver at the given frequencies.
An antenna analyzer would be able to tell you this. This reminds me of a few months ago
when I was testing my transceiver with what I *thought* was a good dummy load.
It turns out I had exceeded the power rating of the dummy load and damaged it (should
have smelled it but I had a head cold so couldn't detect it ;-)).
In that case however all bands were affected. You may have a different situation here.
And I don't know what a *heath antenna* is, It sure sounds like it's an antenna and not
a dummy load which would explain what you are seeing. Dummy loads offer a purely (or almost
purely) resistive (real ) component of impedance to your radio depending on the frequency. The idea
is they allow you to dissipate 100% of the RF energy into it -safely- so you can measure it, tune your AMP/Radio
safely etc. etc. Dummy loads come in various types mainly depending on the amount of power they can
dissipate. I doubt your radio is the problem though.
--Luis, NY6U




________________________________
From: BASILIE <n8nqu@avci.net>
To: ic7000@yahoogroups.com
Sent: Mon, April 12, 2010 9:00:12 AM
Subject: [IC-7000] Re: IC-7000 50 watts on some bans?????

 


Have you measured the TX power into a known good dummy load, bypassing the
tuner? It is unlikely this is a problem with the radio.
Yes,i went into a heath cantenna with no tuner inline and I did check the voltage on pin 3 and 4,I am using a VS-70amp Astron.Here is what I found.

160 meters
100% rf power 20 watts Idle 14.00 volts under load 13.61 volts
50% " " 2 watts " " 13.65 "

80 meters
100% 48 watts " " 13.37 "
50% 5 watts 13.62 "

40 meters
100% 50 watts 13.10 "
50% 8 watts 13.45

20 meters
100% 105 watts 13.29
50% 50 watts 13.05
10 meters 100 watts
100% 100 watts 13.00
50% 50 watts 13.32

I hope this makes sense.

--- In ic7000@yahoogroups. com, "Steve W3AHL" <w3ahl@...> wrote:

Have you measured the TX power into a known good dummy load, bypassing the tuner? It is unlikely this is a problem with the radio.

Also, verify the DC voltage at the radio while transmitting at full power. The best place to measure it is on pins 3 & 4 of the antenna tuner connector. It should be 12.8-13.2 volts to get full power output.

More details on your test method would help.

Steve, W3AHL

--- In ic7000@yahoogroups. com, "BASILIE" <n8nqu@> wrote:

Does anybody know why 10-20 meters I have 100 watts and 40-160 meters only have 50 watts??????I am using the radio with the LDG IT-100.It's got me thinking that I have something major wrong with the radio.Serial Number is 05107xx.Thanks Bill N8NQU.73.... .....






[Non-text portions of this message have been removed]


Re: IC-7000 50 watts on some bans?????

BASILIE <n8nqu@...>
 

Have you measured the TX power into a known good dummy load, bypassing the
tuner? It is unlikely this is a problem with the radio.
Yes,i went into a heath cantenna with no tuner inline and I did check the voltage on pin 3 and 4,I am using a VS-70amp Astron.Here is what I found.

160 meters
100% rf power 20 watts Idle 14.00 volts under load 13.61 volts
50% " " 2 watts " " 13.65 "

80 meters
100% 48 watts " " 13.37 "
50% 5 watts 13.62 "

40 meters
100% 50 watts 13.10 "
50% 8 watts 13.45


20 meters
100% 105 watts 13.29
50% 50 watts 13.05
10 meters 100 watts
100% 100 watts 13.00
50% 50 watts 13.32

I hope this makes sense.

--- In ic7000@yahoogroups.com, "Steve W3AHL" <w3ahl@...> wrote:

Have you measured the TX power into a known good dummy load, bypassing the tuner? It is unlikely this is a problem with the radio.

Also, verify the DC voltage at the radio while transmitting at full power. The best place to measure it is on pins 3 & 4 of the antenna tuner connector. It should be 12.8-13.2 volts to get full power output.

More details on your test method would help.

Steve, W3AHL

--- In ic7000@yahoogroups.com, "BASILIE" <n8nqu@> wrote:

Does anybody know why 10-20 meters I have 100 watts and 40-160 meters only have 50 watts??????I am using the radio with the LDG IT-100.It's got me thinking that I have something major wrong with the radio.Serial Number is 05107xx.Thanks Bill N8NQU.73.........


Re: [IC-7000] OK what should i do next?

Bob Kulow
 

I will be there all 3 days. Staying at the Dayton KOA.

73
Bob WA2UEH

Announcer: You just kicked some butt in the Georgia QSO Party, what are you going to do next?

KB7TBT: I am going to the DAYTON HAMFEST!!!

Anyone else have plans for Dayton?


AT-7000 is not tuning anymore... help

milka1969 <milka1969@...>
 

Hello to all,

After that my driver unit whent in smoke, i order the part and fixed it!

Since then it looks that my AT-7000 will not tune.
I unsrewed the device and checked the red light. It is turning on when i want to tune but there is no noise like it use to do.

Is there a way to check it? Does anyone had the same problem?

Please help!!!!

Many 73 de sw1moz


(No subject)

James KB7TBT
 

If I worked you in the GA QSO Party this weekend I do QSL 100%

I have posted my log file.
http://tinyurl.com/y2djyxb

I want to thank those that stopped by to make contact with me from a bunch of the email groups.
Sorry if I didn't recognize some of you right off the bat, by the time half the day was over on Saturday my brains were soup, it just got worse on Sunday.

It was a great weekend!

James
KB7TBT
www.kb7tbt.com


OK what should i do next?

James KB7TBT
 

Announcer: You just kicked some butt in the Georgia QSO Party, what are you going to do next?

KB7TBT: I am going to the DAYTON HAMFEST!!!

Anyone else have plans for Dayton?



James
KB7TBT
www.kb7tbt.com


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

D C *Mac* Macdonald
 

The matching device (coil or capacitor) doesn't care what
type of antenna you are using; base, center, or top load.
It probably isn't absolutely necessary if you are talking
about 20 meter and higher frequency bands.

A 96-102 inch whip tends to be naturally resonant at the
10-11 meter frequencies. You may STILL need to trim the
big whip a bit to truly reach resonance; a good reason to
start with 102 inches.

With a PERFECT ground plane, that 10 meter antenna will
have a radiation impedance of 36 Ohms. This is close to
a 1.5:1 mismatch (and VSWR). You MAY get some power
foldback on your rig with even this minimal mismatch.

With lower frequencies, losses incurred with loading coils
used to make the antenna simulate resonance when shorter
than normal 1/4 wavelength can cause apparent impedance to
rise making it appear that you are getting a better match.

When you get down to 20 meters, and deteriorating as you
move down in frequency, the shortness (compared to 1/4
wavelength) brings coil and other losses to increase markedly.

High "Q" coils with larger diameters and thicker wires will
reduce losses, but not eliminate those losses. This comes
at the expense of antenna bandwidth with tolerable VSWR.

Any "matching" done at the rig instead of at the antenna
feedpoint, will cause some reduction in actual radiated power.

"Hamstick" type antennas typically use small wire and small
diameters so are always more lossy than "bugcatcher" coil
antennas. They do, however, have an "advantage" of a greater
VSWR bandwidth.

Better "screwdriver" antennas have those larger diameters
and thicker wire and can approach the efficiency of the
"bugcatcher" antennas.

Mounting location also has a large influence on HF mobile
antenna performance. A smaller "screwdriver" such as the
"Little Tarheel" mounted on a truck's side rail toward
the rear will often give performance equal to or better
than a larger "screwdriver" mounted on the bumper or the
trailer hitch!

Mobile HF operation 28 MHz is always a compromise between
convenience and efficiency. It gets rapidly worse as you
move down in frequency.

ALL antennas radiate SOME signal. As the book published
by the folks at Force 12 state, "All antennas work." The
point is that you need to do everything you can to improve
efficiency so that your transmitter's Watts are not wasted.

73 - Mac, K2GKK/5
(Since 30 Nov 53)
HF Mobile Since 62
Oklahoma City, OK

p.s. The actual radiation resistance of a High Q 75 meter
antenna system is in the vicinity of 5 Ohms. That means
that even with the BEST mobile antenna, you are looking at
maybe 90% of your transmitted power being wasted!



__________________________
To: ic7000@yahoogroups.com
From: goldtr8@charter.net
Date: Sun, 11 Apr 2010 22:04:36 +0000
Subject: Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Hi Mac,

You just hit me in the head with at brick.

Matcher as you describe is at the coil between ground at the antenna for what is described by my simple understanding as a screw driver type where you have an inductive coil in the base of the antenna.

In my case if I stay with a hamstick style I would be using an impedance matcher which I believe just goes between the radio and the antenna if I continue to use the internal SWR meter.

Do I have it correct or am I missing something.

Thanks
KD8NNU

--- In ic7000@yahoogroups.com, D C *Mac* Macdonald <k2gkk@...> wrote:


The matching device needed is simply a coil with the
proper inductance SHORTED from the feedpoint to the
chassis ground. This coil along with a small portion
of the loading coil of the antenna forms an "L" network
to match the very low impedance on 40 and even lower
on 75/80 meters to the 50 Ohm impedance of your coax.
It is virtually lossless.

A fixed capacitor at the same location will also serve
to get you a correct match. Try 1,000 or 470 pFd for
75/80 and 470 or 270 for 40. It's been so long that I
have forgotten the actual starting values. Use good
quality MICA caps, the higher voltage rating the better
(within reasonable phyisical size limits).

With the High Sierra HS-1500 (replaced by HS-1800)
one coil is used for all bands from 80M through 10M.

The old Master Mobile (60s and 70s) setup, there was
a manually variable inductor in the same location that
could be reset for each band. I still have that setup
(that I bought in 1962) out in the garage with lots of
other old stuff.

If you don't need help to match your antenna to 50
Ohm coax, you have an antenna that is excessively and
unnecessarily lossy!

73 - Mac, K2GKK/5
(Since 30 Nov 53)
Oklahoma City, OK


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Jack Rucker <jackr1@...>
 

Steve - W3AHL,

I used the "400W" [QRP] Hustlers for years, before giving them away, after comparing with Super Hustlers. With a 50W T-T Scout, the QRP Hustler would get too hot to hold comfortably while tuning. With same TX, mount, & mast, the Super Hustler only got slightly warm, and easily outperformed the skinny coil on every test - TX & RX, while parked. Top hat also improved performance of RM80S & RM40S. 3 or more dB on every A/B comparison between RMxx & RMxx-S was very convincing. When done with distant stations, they didn't know which antennas I was testing - just A & B.

I was glad to get rid of the regular Hustlers. If still available, I'd compare temperature of both after a 2 minute key down. I'd also compare them on my 10 inch fence-post FS meter while transmitting.

I have run an Ameritron ALS-500M amp on the Super Hustlers, and with the Little Tarheel, with no problems - except for some discoloration of Tarheel coil. They offered to replace it at a Hamfest, but it is mostly cosmetic, & runs cooler with top hat & longer tip rod [using less coil].

A shortened vertical works best with a top loaded coil, which is seldom practical. A center loaded is next, & base loaded is really a compromise - but works, especially if entire coil is above vehicle. If parallel to metal body, & only a couple of inches away, it's even worse, & pattern really skewed. If the coil is near body, & moves at all, the VSWR is very unstable.

Jack_son
============================================

--- In ic7000@yahoogroups.com, "Steve W3AHL" <w3ahl@...> wrote:

Jack,

I basically agree. It is always better to use a good antenna than to try to use a tuner with a poor antenna. That's why I suggested a Hi-Q or similar tunable mobile instead of the Shark/ Ham Stix with a tuner.

I do a lot of portable operation, so putting up a well-matched antenna often isn't feasible. But putting a tuner at the station end of the coax is not a good solution either. I'm gettting an SG-237 so the matching can be done at the feed point, but that's so I can cover the MARS frequencies with a simple-to-deploy wire.

The main reason I use an autotuner with my tuned dipoles is to reduce the stress on the 7K's PA as the SWR gets above 2.5:1, primarily on 75M. The fan dipole is already cut for 80/40/30, so adding 75M isn't a good option for me. And they aren't THAT lossy below 15 MHz.

I've used Hustler "Super" resonators, but they are anything but super. They have slightly broader bandwidth than the standard ones, but are also slightly more lossy. And you still have to get out and adjust the stinger if you move 50KHz on 75M.

Steve, W3AHL


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Goldtr8 \(KD8NNU\)
 

Hi Mac,

You just hit me in the head with at brick.

Matcher as you describe is at the coil between ground at the antenna for what is described by my simple understanding as a screw driver type where you have an inductive coil in the base of the antenna.

In my case if I stay with a hamstick style I would be using an impedance matcher which I believe just goes between the radio and the antenna if I continue to use the internal SWR meter.

Do I have it correct or am I missing something.

Thanks
KD8NNU

--- In ic7000@yahoogroups.com, D C *Mac* Macdonald <k2gkk@...> wrote:


The matching device needed is simply a coil with the
proper inductance SHORTED from the feedpoint to the
chassis ground. This coil along with a small portion
of the loading coil of the antenna forms an "L" network
to match the very low impedance on 40 and even lower
on 75/80 meters to the 50 Ohm impedance of your coax.
It is virtually lossless.

A fixed capacitor at the same location will also serve
to get you a correct match. Try 1,000 or 470 pFd for
75/80 and 470 or 270 for 40. It's been so long that I
have forgotten the actual starting values. Use good
quality MICA caps, the higher voltage rating the better
(within reasonable phyisical size limits).

With the High Sierra HS-1500 (replaced by HS-1800)
one coil is used for all bands from 80M through 10M.

The old Master Mobile (60s and 70s) setup, there was
a manually variable inductor in the same location that
could be reset for each band. I still have that setup
(that I bought in 1962) out in the garage with lots of
other old stuff.

If you don't need help to match your antenna to 50
Ohm coax, you have an antenna that is excessively and
unnecessarily lossy!

73 - Mac, K2GKK/5
(Since 30 Nov 53)
Oklahoma City, OK




To: ic7000@yahoogroups.com
From: goldtr8@...
Date: Sun, 11 Apr 2010 13:53:00 +0000
Subject: Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Gents

I did a search on the Hi-Q and for 40 & 80 meters it mentions
that you still might need a matching device. This was for the
units with the 3 inch coils. Also the efficiency at low
frequencies does not appear to be very good as I looked at
specs for more of the types that they have available.

Right now I am thinking tuner so I can use the radio effectively
and do a lot more studying regarding antennas. There is way more
to know about antennas than I know at this point in time and the
Shark/Hamstick allows me to use the radio and if I break one off
on the jeep its no big deal.

I take the Jeep off road quite a bit so I realize that compromise
will enter into the picture. I would not be happy with damaging
an expensive screw driver unit.

But the Hi-Q does look interesting


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems]

Adrian <vk4tux@...>
 

On Sun, 2010-04-11 at 05:38 -0700, Scott Scheirman wrote:

I think the poster tried to be sarcastic, rather than literal. You
know, as in "35 ohm resistors" = "snake oil".


Jut my .02


Scott
AD7XV
Fine, yes I apologise to Jack for my misunderstanding, thankyou.

vk4tux (not KV4TUX)


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Steve W3AHL
 

Don,

Jack's point was that it is better to have the matching circuit at the feed point, rather than at the station end in order to reduce coaxial feed line losses due to high SWR. If a tuner is used in the station, it is better to used 400-600 ohm ladder line to the entry point to minimize loss, then use a balun and coax to the tuner.

The reason that most mobile HF antennas need additional matching circuits (not built-in to the antenna base) is that the feed point impedance varies significantly depending upon how it is mounted. The "autotuner" (actually a matching coupler, since it doesn't "tune" the antenna resonance)is convenient for mobile use where the coax is short. But if you try to use it to correct a non-resonant loaded vertical, the losses increase very rapidly. Which is why screwdriver styles are popular.

Steve, W3AHL

--- In ic7000@yahoogroups.com, "Don" <goldtr8@...> wrote:

Hi Jack,

You mention if the tuner is used on the wrong end of the coax. I am trying to find reference to this on the web, but so far no luck. Please would explain further what you mean.

The tuner that I would be getting would have a reasonably short coax between the transmitter and tune then the longer coax to the antenna.

Now in my installation I do have a long coax between the tuner and the transmitter as this was orgionally set up for CB and when installed last year it was recommended that I purchase this longer line to better match the system. I am not sure this is true anymore as I am learning about HF operation. In fact it might be part of my tuning problem.

Thanks for you help.

KD8NNU Don

--- In ic7000@yahoogroups.com, Jack Rucker <jackr1@> wrote:

KV4TUX,

I was guilty of not keeping tongue in cheek, so perhaps you had trouble understanding my English: "...If you want more loss, a dummy load looks like a perfect antenna, on all bands."

When antenna resonance can be achieved by simple adjustment of antenna, and Z can be matched by base coil or cap, why use a tuner at the transmitter end? VSWR should be minimized by resonating antenna before attempting to compensate with a tuner. Using a tuner, when not needed, introduces more loss. Adjusting base Z match & antenna resonance is best made without a tuner in the circuit.

Some base matching coils have adjustable taps, but for my 40M Tarheel, they recommend a fixed coil optimized for 40M, & leaving it in place for higher bands. This works well for me, although I had used a tapped coil at base of bug-catchers in earlier years, & marked 80, 40, & 20M taps.

I thought that even someone not too familiar with English would understand that I _do_ consider resistors to be very lossy. Tuners introduce unnecessary loss also, especially when used at the wrong end of coax, when a simple base Z matching coil or cap is needed.

Jack_son
==========================================
..snip..


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

D C *Mac* Macdonald
 

The matching device needed is simply a coil with the
proper inductance SHORTED from the feedpoint to the
chassis ground. This coil along with a small portion
of the loading coil of the antenna forms an "L" network
to match the very low impedance on 40 and even lower
on 75/80 meters to the 50 Ohm impedance of your coax.
It is virtually lossless.

A fixed capacitor at the same location will also serve
to get you a correct match. Try 1,000 or 470 pFd for
75/80 and 470 or 270 for 40. It's been so long that I
have forgotten the actual starting values. Use good
quality MICA caps, the higher voltage rating the better
(within reasonable phyisical size limits).

With the High Sierra HS-1500 (replaced by HS-1800)
one coil is used for all bands from 80M through 10M.

The old Master Mobile (60s and 70s) setup, there was
a manually variable inductor in the same location that
could be reset for each band. I still have that setup
(that I bought in 1962) out in the garage with lots of
other old stuff.

If you don't need help to match your antenna to 50
Ohm coax, you have an antenna that is excessively and
unnecessarily lossy!

73 - Mac, K2GKK/5
(Since 30 Nov 53)
Oklahoma City, OK




To: ic7000@yahoogroups.com
From: goldtr8@charter.net
Date: Sun, 11 Apr 2010 13:53:00 +0000
Subject: Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Gents

I did a search on the Hi-Q and for 40 & 80 meters it mentions
that you still might need a matching device. This was for the
units with the 3 inch coils. Also the efficiency at low
frequencies does not appear to be very good as I looked at
specs for more of the types that they have available.

Right now I am thinking tuner so I can use the radio effectively
and do a lot more studying regarding antennas. There is way more
to know about antennas than I know at this point in time and the
Shark/Hamstick allows me to use the radio and if I break one off
on the jeep its no big deal.

I take the Jeep off road quite a bit so I realize that compromise
will enter into the picture. I would not be happy with damaging
an expensive screw driver unit.

But the Hi-Q does look interesting


Re: [IC-7000] RTTY or CW to check SWR on 7000 I am having problems

Goldtr8 \(KD8NNU\)
 

Hi Jack,

You mention if the tuner is used on the wrong end of the coax. I am trying to find reference to this on the web, but so far no luck. Please would explain further what you mean.

The tuner that I would be getting would have a reasonably short coax between the transmitter and tune then the longer coax to the antenna.

Now in my installation I do have a long coax between the tuner and the transmitter as this was orgionally set up for CB and when installed last year it was recommended that I purchase this longer line to better match the system. I am not sure this is true anymore as I am learning about HF operation. In fact it might be part of my tuning problem.

Thanks for you help.

KD8NNU Don

--- In ic7000@yahoogroups.com, Jack Rucker <jackr1@...> wrote:

KV4TUX,

I was guilty of not keeping tongue in cheek, so perhaps you had trouble understanding my English: "...If you want more loss, a dummy load looks like a perfect antenna, on all bands."

When antenna resonance can be achieved by simple adjustment of antenna, and Z can be matched by base coil or cap, why use a tuner at the transmitter end? VSWR should be minimized by resonating antenna before attempting to compensate with a tuner. Using a tuner, when not needed, introduces more loss. Adjusting base Z match & antenna resonance is best made without a tuner in the circuit.

Some base matching coils have adjustable taps, but for my 40M Tarheel, they recommend a fixed coil optimized for 40M, & leaving it in place for higher bands. This works well for me, although I had used a tapped coil at base of bug-catchers in earlier years, & marked 80, 40, & 20M taps.

I thought that even someone not too familiar with English would understand that I _do_ consider resistors to be very lossy. Tuners introduce unnecessary loss also, especially when used at the wrong end of coax, when a simple base Z matching coil or cap is needed.

Jack_son
==========================================

On Sun, 2010-04-11 at 02:27 -0400, Jack Rucker wrote:



Does everyone own stock in tuner companies? A transmitter, receiver, &
antenna are required for any station. In a few cases, tuners may be
handy, or required.

I have not used an antenna tuner at my fixed station for decades. I
don't carry a tuner when backpacking, or ship one overseas, when
working from a DX location. I certainly don't need a mobile tuner,
when running my tunable Tarheel 'screwdriver', or adjustable Super
Hustler resonators.

It is a wonder someone doesn't sell non-inductive 35 ohm resistors,
to mount in series with HF mobile antenna base. Perfect 50 ohm match,
no arcing, & cheaper than any tuner. Another 150 ohm resistor, on a
Tee at transmitter, would make sure you only have 3:1 VSWR when you
forget to connect your antenna. If you want more loss, a dummy load
looks like a perfect antenna, on all bands.

I´d go back to your antenna books and refresh your knowledge.

Resistance in series = loss.

Placing a resistor in series will attenuate both the received and
transmitted signal.

Just because it looks good on a swr meter doesn't mean it it is not
wasting power as heat,
just like a Dummy Load does.

A tuner uses Inductive and capacitive reactance to provide impedance to
match the load with far less loss (If required at all).

vk4tux


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