Date   

Daiwa Rotator update- success!

John E. Beech
 

Hi All,
Having retrieved the DC7011 Round Controller ( why is it called that?) from the clubhouse I replaced the 6 way cable and it was as dead as a door nail. SO I took the lid off & replaced the internal fuse and it is now all working, including the dial read out. The servo mechanism in the controller sounds a bit clunky & erratic so I lubricated the gears, but I can live with that. It seems to be reasonably accurate ( + or - a bout 2 deg), both the rotator and the indicator stop on South when turning clockwise; the indicator stops on South when turning anticlockwise but the rotator runs on for a few seconds or about 10 deg past South before stopping. It is also possible to rotate it n one degree increments with short pushes on the controll switches. This is all with out any load/aerial on the rotator. So a successful afternoon & no need to strip the thing down.
All I need to do no is to re-engineer my mount to take this rotator before the week ends activities. Thanks agin to all those who supplied information on this beast.

de John G8SEQ
PS. I didn't bother trying to retrieve the 6 way cable from the installation at the club house (too much like hard work); I suspect the fault was there. It had a D-type connector for ease of dismantling after every club night & I'm guessing a wire has been pulled off in the plug.


Re: QO100 This Thursday

Nick Gregory G0HIK
 

A great activation today. The weather was a bit rough initially, but the rain eased and the wind backed off by the end.

All Summit operators managed to work each other as well as a few other stations.

Hopefully I'll be out again next week.

Nick G0HIK


Re: 70 Watt amplifier kit for 23cms coming soon

Martin Cranage, G8OFA
 

I would also be interested. 
73, Martin G8OFA

--
Martin, G8OFA


Re: 70 Watt amplifier kit for 23cms coming soon

Garyov
 

Be interested in a Kit if still available please.
G4BJD Gary


Daiwa Rotator update

John E. Beech
 

Hi All,
Thanks to all of you that replied. I now have the information I require to sort the rotator. From measurements I've made, I think the rotator & its pot are OK. I think the fault maybe a break in the multicore cable, but I can't be sure until I get hold of the controller & cable. It is locked in a cupboard at the club house, which I don't have immediate access to.

de John G8SEQ CARS Hon. Sec..


Re: Looking to test my 23cm setup

Alan
 

Hi Dave,

I would be up for a test from home but unfortunately will be out in the PM tomorrow...Do let us know if you are out again...

73 Alan GM0USI   IO75uv



07785744643

info@...

www.alandimmick.com

instagram @alandimmick

Studio 331

60-64 Osborne St

South Block

Glasgow

G1 5QH






From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Dave G6HEF <hardknottdave@...>
Sent: 01 July 2020 22:31
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: [UKMicrowaves] Looking to test my 23cm setup
 

I have recently got my 23cm setup improved with a masthead box containing a G4BAO power amp and a G4DDK VLNA.

All I need now is to make some QSOs, however I can only operate from a remote site about a mile from my home QTH. Unfortunately there isn't currently room for a 2m antenna on the mast at the same time (A job to sort, admittedly) So I am calling random CQ directly on 23cm with no reply as yet and I'm getting bored of sitting around! So, looking to setup a sked or two tomorrow afternoon/evening. (02/07/2020). 

Take off from here is limited to anything west of a line drawn roughly between Barrow-in-Furness and just west of London due to a big thing called Black Combe, although always up for a challenge. I am located in IO84 so Lancashire/Wirral/GD/NI/EI perhaps GW? Perhaps even western GM land? etc, etc.

Would be wonderful to get a signal report on TX prior to doing a check log on VHF NFD

Thanks
73
Dave
G6HEF


Virus-free. www.avast.com


Looking to test my 23cm setup

Dave G6HEF
 

I have recently got my 23cm setup improved with a masthead box containing a G4BAO power amp and a G4DDK VLNA.

All I need now is to make some QSOs, however I can only operate from a remote site about a mile from my home QTH. Unfortunately there isn't currently room for a 2m antenna on the mast at the same time (A job to sort, admittedly) So I am calling random CQ directly on 23cm with no reply as yet and I'm getting bored of sitting around! So, looking to setup a sked or two tomorrow afternoon/evening. (02/07/2020). 

Take off from here is limited to anything west of a line drawn roughly between Barrow-in-Furness and just west of London due to a big thing called Black Combe, although always up for a challenge. I am located in IO84 so Lancashire/Wirral/GD/NI/EI perhaps GW? Perhaps even western GM land? etc, etc.

Would be wonderful to get a signal report on TX prior to doing a check log on VHF NFD

Thanks
73
Dave
G6HEF


Re: DAIWA 7500a Rotator

Tony G4NBS
 

Been a while since I took mine apart, though I might do so again shortly as it has jammed and recently been replaced.
Can be messy and if you open it up the wrong way the ball bearings will go everywhere so best be prepared.
Mine has got limit switches and I recall it was a bit of fun reassembling it so that they behaved whilst getting the indicator in the correct position.
Guess if you mark the case as you split it so that you put things together readily aligned that shouldn't be a problem but I repainted mine as well as fitting new bearings and pot so wasn't an option for me.

Thumbs up for Hammerite and its special metal primer - no corrosion on it after 10 years up in the elements and the stainless hardware was easily undone, unlike the original paint and bolts supplied from Japan.

Good luck
73
Tony G4NBS


Re: DAIWA 7500a Rotator

ian hope (2E0IJH)
 

This site's quite a good one, http://www.dl3lar.de/KRx00.html
 
Ian
M5IJH

 
 
Sent: Wednesday, July 01, 2020 at 8:27 PM
From: "ian hope (2E0IJH)" <ian@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] DAIWA 7500a Rotator
A daiwa 7500 is basicily a  G400/g600 and has the same Pot, I have quite a few 2nd hand spare ones if you need one, It's a 500 ohm pot.
 
I would change the balls whilst you in there 99 3/8 steel ones you want
 
If you look up g400/g600 repair on the net there are loads of pictures where people have stripped them down, Kenpro made the rotator heads for Daiwa so effectivly there the same
 
Ian
M5IJH
 
 
Sent: Wednesday, July 01, 2020 at 8:18 PM
From: "R Hopkins via groups.io" <gw4nos@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] DAIWA 7500a Rotator
Hi John

I had my rotator in bits a few weeks ago. It don't think the pot would be hard to replace but I
think it's driven by a separate gear. Making sure that gear is in the right position would be the
hardest part to get right. The pot is 500 Ohms. You can check it from the shack if you disconnect
pin 1 on the controller. Mine hasn't got stop switches as shown on the diagram.

Roger GW4NOS
On Wed, 01 Jul 2020 18:04:26 +0100, you wrote:

>Hi All,
> Has anyone had any experience of replacing the feedback potentiometer in a Daiwa 7500 a Antenna Rotator?
>
>The diagram I've looked at on line doesn't show a value for this pot.. Anyone know what it is? Does it actually matter - it looks as though it just acts as a voltage divider.
>
>When I split the casing apart are a lot of loose bits likely to fall out?
>
>de John G8SEQ
>
>




 


Re: DAIWA 7500a Rotator

ian hope (2E0IJH)
 

A daiwa 7500 is basicily a  G400/g600 and has the same Pot, I have quite a few 2nd hand spare ones if you need one, It's a 500 ohm pot.
 
I would change the balls whilst you in there 99 3/8 steel ones you want
 
If you look up g400/g600 repair on the net there are loads of pictures where people have stripped them down, Kenpro made the rotator heads for Daiwa so effectivly there the same
 
Ian
M5IJH

 
 
Sent: Wednesday, July 01, 2020 at 8:18 PM
From: "R Hopkins via groups.io" <gw4nos@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] DAIWA 7500a Rotator
Hi John

I had my rotator in bits a few weeks ago. It don't think the pot would be hard to replace but I
think it's driven by a separate gear. Making sure that gear is in the right position would be the
hardest part to get right. The pot is 500 Ohms. You can check it from the shack if you disconnect
pin 1 on the controller. Mine hasn't got stop switches as shown on the diagram.

Roger GW4NOS
On Wed, 01 Jul 2020 18:04:26 +0100, you wrote:

>Hi All,
> Has anyone had any experience of replacing the feedback potentiometer in a Daiwa 7500 a Antenna Rotator?
>
>The diagram I've looked at on line doesn't show a value for this pot.. Anyone know what it is? Does it actually matter - it looks as though it just acts as a voltage divider.
>
>When I split the casing apart are a lot of loose bits likely to fall out?
>
>de John G8SEQ
>
>




 


Re: DAIWA 7500a Rotator

R Hopkins
 

Hi John

I had my rotator in bits a few weeks ago. It don't think the pot would be hard to replace but I
think it's driven by a separate gear. Making sure that gear is in the right position would be the
hardest part to get right. The pot is 500 Ohms. You can check it from the shack if you disconnect
pin 1 on the controller. Mine hasn't got stop switches as shown on the diagram.

Roger GW4NOS

On Wed, 01 Jul 2020 18:04:26 +0100, you wrote:

Hi All,
Has anyone had any experience of replacing the feedback potentiometer in a Daiwa 7500 a Antenna Rotator?

The diagram I've looked at on line doesn't show a value for this pot.. Anyone know what it is? Does it actually matter - it looks as though it just acts as a voltage divider.

When I split the casing apart are a lot of loose bits likely to fall out?

de John G8SEQ


Re: QO100 This Thursday

Nick Gregory G0HIK
 

We have another activator now, Caralyn G6WRW on Walton Hill, Stourbridge

ETA  11:00 - 12:00 BST

G6WRW/P 2400.255
G4VFL/P    2400.300
G0HIK/P    2400.350  All +/-

Nick G0HIK


Re: Scavenging parts

Paul G8KFW
 

Hi all 

If I find any front pointing radar dishes is there any interest ?  and how much £

 

They would be commercial  whether radar dishes including  wave guide swivels and

Control motors to move it X & Y  possibly a few 8 to 10 Ghz  RF  unites available

 

I shipped out  8 pallets of aircraft electronic boxes  including radio

But I have to make more room so loads of BAC 111 bits to go

To make room for  Hawk spears

 

Regards Paul  

 


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of militaryoperator via groups.io
Sent: 01 July 2020 16:19
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Scavenging parts

 

No idea, plate was too far gone. 

 

EKCO made

 

Ben

 

 

-----Original Message-----

From: Paul G8KFW <paul@...>
To: UKMicrowaves@groups.io
Sent: Wed, 1 Jul 2020 15:26
Subject: Re: [UKMicrowaves] Scavenging parts

Hi what was the nose radar from military or civil

 

Paul

 


From: UKMicrowaves@groups.io [mailto: UKMicrowaves@groups.io ] On Behalf Of militaryoperator via groups.io
Sent: 01 July 2020 13:03
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Scavenging parts

 

Took my nose radar apart. 

 

Guess the most useful thing is the 46cm dish. 

 

Still, interesting project.  What's the waveguide with the 4 screw-like things on it, top right?

 

DSCF2519.JPG

 

 

odd.JPG

 

 

 

 

 

--------------------------------------

Curator, Owner and Display coordinator

Military Wireless Museum

Kidderminster, UK.

 

This message was meant for the recipient

Any likeness to persons living or dead is odd

---------------------------------------

 


--
Paul Bicknell G8KFW   South Coast UK


--
Paul Bicknell G8KFW   South Coast UK


DAIWA 7500a Rotator

John E. Beech
 

Hi All,
Has anyone had any experience of replacing the feedback potentiometer in a Daiwa 7500 a Antenna Rotator?

The diagram I've looked at on line doesn't show a value for this pot.. Anyone know what it is? Does it actually matter - it looks as though it just acts as a voltage divider.

When I split the casing apart are a lot of loose bits likely to fall out?

de John G8SEQ


Re: Vivaldi ant

militaryoperator
 

Many thanks, Kent. 

Ben.



Subject: Re: [UKMicrowaves] Vivaldi ant
Think of it as another way to feed a horn.
Hard to get a Vivaldi above 8 dBi or so gain.
Ridged horns can easily go to 20 dBi.
Of course the EMI horn is playing other games to get a more
constant Antenna Factor.
The Copper ones are mine, the 'PTI' is one at the EMI
lab I use for FCC/CE certifications.




Re: Vivaldi ant

KENT BRITAIN
 



Think of it as another way to feed a horn.

Hard to get a Vivaldi above 8 dBi or so gain.
Ridged horns can easily go to 20 dBi.

Of course the EMI horn is playing other games to get a more
constant Antenna Factor.

The Copper ones are mine, the 'PTI' is one at the EMI
lab I use for FCC/CE certifications.



On Wednesday, July 1, 2020, 10:29:16 AM CDT, militaryoperator via groups.io <military1944@...> wrote:


Re: Vivaldi ant

militaryoperator
 












Hi Kent. Ok, but do you get better results, gain etc if the viv is mounted in a horn like in the picture?
as opposed to mounting the viv in open space by itself.

Ben.




Subject: Re: [UKMicrowaves] Vivaldi ant

Another example would be WG16,  suggested frequency range, 8-12 GHz.

Put a ridge down the middle, ridged waveguide, and the suggested frequency range
is now 5-12 GHz.     With the Vivaldi, how narrow you can make the slot sets the
upper frequency limit.  Width of the opening sets the lower frequency limit.
Kent

On Wednesday, July 1, 2020, 6:10:58 AM CDT, militaryoperator via groups.io <military1944@...> wrote:


Is there a benefit for mounting a Vivaldi in a horn enclosure?

Is this better than having the Vivaldi in the open?

s-l1600 (2).jpg

Ben



Re: Scavenging parts

militaryoperator
 

No idea, plate was too far gone. 

EKCO made

Ben



-----Original Message-----
From: Paul G8KFW <paul@...>
To: UKMicrowaves@groups.io
Sent: Wed, 1 Jul 2020 15:26
Subject: Re: [UKMicrowaves] Scavenging parts

Hi what was the nose radar from military or civil
 
Paul
 

From: UKMicrowaves@groups.io [mailto: UKMicrowaves@groups.io ] On Behalf Of militaryoperator via groups.io
Sent: 01 July 2020 13:03
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Scavenging parts
 
Took my nose radar apart. 
 
Guess the most useful thing is the 46cm dish. 
 
Still, interesting project.  What's the waveguide with the 4 screw-like things on it, top right?
 
DSCF2519.JPG
 
 
odd.JPG
 
 
 
 
 
--------------------------------------
Curator, Owner and Display coordinator
Military Wireless Museum
Kidderminster, UK.
 
This message was meant for the recipient
Any likeness to persons living or dead is odd
---------------------------------------
 

--
Paul Bicknell G8KFW   South Coast UK


Re: QO100 This Thursday

Nick Gregory G0HIK
 

Great.

Weather forecast has gotten worse, lets hope it doesn't get too wet.

Nick G0HIK


Re: Scavenging parts

KENT BRITAIN
 

r

DSCF2519.JPG

 

  Zooming in it looks like your dish also has a Cuttler Feed
Note the 90 deg twist in the feed.   For years I wondered
"Didn't they know what polarization they wanted before they
 did the design?"
There is a surface current that runs back down the outside of
the WG. Goes into the dish, and gets radiated.  SIDELOBES!
The 90 deg twist makes the signals at the feed cross polarized
 to the sideblobes.    Someone did know what they were doing.
70 years ago!    Kent


 

 

 

 

 

--------------------------------------

Curator, Owner and Display coordinator

Military Wireless Museum

Kidderminster, UK.

 

This message was meant for the recipient

Any likeness to persons living or dead is odd

---------------------------------------

 


--
Paul Bicknell G8KFW   South Coast UK

7601 - 7620 of 64337