Date   

Re: Off-Set Dish Mounting Ideas

KENT BRITAIN
 

Hi Gedas

Here in Texas, back in the late 80's, we had a lad who absolutely claimed he had to have the gain and went portable (No hill topping around here!) with a 10 foot dish.    We never worked him at a remote site.  He just didn't understand the issues of pointing a dish with a 7/10th deg beamwidth in the vertical and horiz planes.
Frequency uncertainty was a bit of an issue as well back then.    GPS? What's GPS?  Oh yea those $1000 things.  Didn't help with pointing or frequency!   In our flat areas I firmly believe that a 20 dBi horn at 20-25 feet will beat a 3 foot dish on a camera tripod 99% of the time on non-LOS paths.   Much easier to point as well!  73 Kent 2E0VAA/W5     (I really find it unusual that OFFCOM let's you keep your old licenses active)

On Sunday, August 22, 2021, 01:45:10 PM CDT, Gedas <w8bya@...> wrote:


WOW....you made me spit out me coffee all over the carpet hi-hi.....1.8m offset dish that was for "hill topping".....holly Toledo.

On an unrelated note I have had two PM's asking where I got the mounts for the Italian feed I plan to use. The short answer is off E-Bay. Cost almost nothing. They intend you to use one but since the feed is long enough I saw a way to use two of these clam-shell mounts for some extra stiffness. Here is a typical example:

https://www.ebay.com/itm/363091944521


Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 2:19 PM, John Fell wrote:
And the downside of mounting on its side is the offset from the vertical mast to get much EL- think jack thrust and dish upper  rim against the vertical mast - something has to give .Been there done that .....
The "on its side " mount dish  technique was first propounded by my old friend Mike G3JVL and Andy G4JNT and I used it with a 1.8m offset when we used to go Hilltopping on 10GHz back in the early 90's .That was OK coz I made a short section of triangle section mast with the dish pivot above the top end of the support mast so it could jack to 60 +degrees for high Summer Sun.All mounted on a large boat trailer and towed by a Landy. Heard my first 10GHz EME CW from WA7CJO in 1991 using the dish on my drive , in the days before we built the G4RFR 12Ft system.

These days digital stuf allows shack positioning and there are (here in UK) Many beacons to calibrate AZ and the Sun to set the EL.

73
JOhn
G0API

73
John
G0API

On Sun, 22 Aug 2021 at 18:45, Gedas <w8bya@...> wrote:

Hi Kent. You know that is not something I ever considered not is it anything I have every heard of anyone here in the states doing.....very interesting. I am very lucky as an old friend has given me an absolute reading digital inclinometer with remote reading display. I think it was actually made there in the UK or marketed by an outfit in the UK. I can strap to the dish in the right spot and give me a fair idea of where zero degrees is at. Thank you. 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 12:47 PM, KENT BRITAIN wrote:
The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

Gedas
 

Hmmm, I guess I need to give this more thought. To be fair I have been in front of the 10 GHz rig trying to hand out points during the contest and have not had time to chew on any of this. Conditions suck BTW !

As far as the tower and mast being vertical, I can say that it is not depending which way the mast is rotated. The tower is 70' and while I tried to set it in 7' of concrete plumb I am sure it is off at the top. But then the 15' of 2" OD 3/8" thick 6061 aluminum mast sticking out the top. I am pretty sure at that 85' level the dish may be several degrees down in one direction and several degrees up 180 degrees the other way.

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 2:45 PM, Barry VE4MA wrote:

The problem with side mounting is that you don't get any elevation adjustment....so your tower has to be very straight up/ down and if you are using RS close in you cannot optimize it. 

Gedas I will send a power point later

Barry VE4MA

On Sun, Aug 22, 2021 at 11:47 AM KENT BRITAIN <WA5VJB@...> wrote:
The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

Gedas
 

WOW....you made me spit out me coffee all over the carpet hi-hi.....1.8m offset dish that was for "hill topping".....holly Toledo.

On an unrelated note I have had two PM's asking where I got the mounts for the Italian feed I plan to use. The short answer is off E-Bay. Cost almost nothing. They intend you to use one but since the feed is long enough I saw a way to use two of these clam-shell mounts for some extra stiffness. Here is a typical example:

https://www.ebay.com/itm/363091944521


Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 2:19 PM, John Fell wrote:

And the downside of mounting on its side is the offset from the vertical mast to get much EL- think jack thrust and dish upper  rim against the vertical mast - something has to give .Been there done that .....
The "on its side " mount dish  technique was first propounded by my old friend Mike G3JVL and Andy G4JNT and I used it with a 1.8m offset when we used to go Hilltopping on 10GHz back in the early 90's .That was OK coz I made a short section of triangle section mast with the dish pivot above the top end of the support mast so it could jack to 60 +degrees for high Summer Sun.All mounted on a large boat trailer and towed by a Landy. Heard my first 10GHz EME CW from WA7CJO in 1991 using the dish on my drive , in the days before we built the G4RFR 12Ft system.

These days digital stuf allows shack positioning and there are (here in UK) Many beacons to calibrate AZ and the Sun to set the EL.

73
JOhn
G0API

73
John
G0API

On Sun, 22 Aug 2021 at 18:45, Gedas <w8bya@...> wrote:

Hi Kent. You know that is not something I ever considered not is it anything I have every heard of anyone here in the states doing.....very interesting. I am very lucky as an old friend has given me an absolute reading digital inclinometer with remote reading display. I think it was actually made there in the UK or marketed by an outfit in the UK. I can strap to the dish in the right spot and give me a fair idea of where zero degrees is at. Thank you. 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 12:47 PM, KENT BRITAIN wrote:
The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

Pete - GM4BYF
 

last email :- Completely = completely agree

73
Pete GM4BYF
On 22/08/21 18:58, Pete - GM4BYF via groups.io wrote:

Completely Kent and very often the feed arm is the along the azimuth direction. True for both my 10GHz, 31" dish and my larger 13cm dish.

73
Pete GM4BYF
On 22/08/21 17:47, KENT BRITAIN wrote:
The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








--
vry 73
Pete GM4BYF

--
vry 73
Pete GM4BYF


Re: Off-Set Dish Mounting Ideas

John Fell
 

And the downside of mounting on its side is the offset from the vertical mast to get much EL- think jack thrust and dish upper  rim against the vertical mast - something has to give .Been there done that .....
The "on its side " mount dish  technique was first propounded by my old friend Mike G3JVL and Andy G4JNT and I used it with a 1.8m offset when we used to go Hilltopping on 10GHz back in the early 90's .That was OK coz I made a short section of triangle section mast with the dish pivot above the top end of the support mast so it could jack to 60 +degrees for high Summer Sun.All mounted on a large boat trailer and towed by a Landy. Heard my first 10GHz EME CW from WA7CJO in 1991 using the dish on my drive , in the days before we built the G4RFR 12Ft system.

These days digital stuf allows shack positioning and there are (here in UK) Many beacons to calibrate AZ and the Sun to set the EL.

73
JOhn
G0API

73
John
G0API


On Sun, 22 Aug 2021 at 18:45, Gedas <w8bya@...> wrote:

Hi Kent. You know that is not something I ever considered not is it anything I have every heard of anyone here in the states doing.....very interesting. I am very lucky as an old friend has given me an absolute reading digital inclinometer with remote reading display. I think it was actually made there in the UK or marketed by an outfit in the UK. I can strap to the dish in the right spot and give me a fair idea of where zero degrees is at. Thank you. 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 12:47 PM, KENT BRITAIN wrote:
The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

Pete - GM4BYF
 

Completely Kent and very often the feed arm is the along the azimuth direction. True for both my 10GHz, 31" dish and my larger 13cm dish.

73
Pete GM4BYF
On 22/08/21 17:47, KENT BRITAIN wrote:

The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








--
vry 73
Pete GM4BYF


Re: Off-Set Dish Mounting Ideas

Gedas
 

Hi Kent. You know that is not something I ever considered not is it anything I have every heard of anyone here in the states doing.....very interesting. I am very lucky as an old friend has given me an absolute reading digital inclinometer with remote reading display. I think it was actually made there in the UK or marketed by an outfit in the UK. I can strap to the dish in the right spot and give me a fair idea of where zero degrees is at. Thank you. 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 12:47 PM, KENT BRITAIN wrote:

The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

Gedas
 

Hi John. Thank you very much for passing that along. Interesting how you moved the pivot point away from the dish itself and made it a separate assm. I was thinking of making the pivot right off the back of the dish but now you have my thinking. I need to study the images again, more closely to see how the linear actuator is mounted and allowed to travel (in an angular sense). Thank you again ! 73

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 8/22/2021 12:37 PM, John Fell wrote:

Here are 3 pics of the way I did my 60cm offset EL back in the last Century - it has survived one Hurricane and plenty of  lesser wind events .
All components are MildSteel - not the lightest , but it is strong and allows easy welding .The clamps are a mixture of standard Scaf and exhaust U bolts .
The mast extension Aluminium is scaf above the rotator cage .The jack is around 12" stroke , which gets the EL upto around 30 degrees - good for Geosats and a fair amount of Sun testing or EME on 10GHz .The "tin Can" on the jack is actually an aluminium Diff pump oil container with the base cut off - it is sealed at the neck and prevents rain passing the rubber body to stem seal. 
The feeds currently deployed are an original 27MHz ref Octagon LNB and a Super VE4MA for 5760MHz , offset in the horizontal plane .

73
John
G0API

On Sun, 22 Aug 2021 at 17:06, Gedas <w8bya@...> wrote:
GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

KENT BRITAIN
 

The common technique is to mount the dish with the feed to the side instead of the bottom.
Now it is very easy to tell when the dish is pointing at the horizon and the offset angles are taken up in your rotator!   Kent G8EMY/W5

On Sunday, August 22, 2021, 11:06:34 AM CDT, Gedas <w8bya@...> wrote:


GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Re: Off-Set Dish Mounting Ideas

John Fell
 

Here are 3 pics of the way I did my 60cm offset EL back in the last Century - it has survived one Hurricane and plenty of  lesser wind events .
All components are MildSteel - not the lightest , but it is strong and allows easy welding .The clamps are a mixture of standard Scaf and exhaust U bolts .
The mast extension Aluminium is scaf above the rotator cage .The jack is around 12" stroke , which gets the EL upto around 30 degrees - good for Geosats and a fair amount of Sun testing or EME on 10GHz .The "tin Can" on the jack is actually an aluminium Diff pump oil container with the base cut off - it is sealed at the neck and prevents rain passing the rubber body to stem seal. 
The feeds currently deployed are an original 27MHz ref Octagon LNB and a Super VE4MA for 5760MHz , offset in the horizontal plane .

73
John
G0API

On Sun, 22 Aug 2021 at 17:06, Gedas <w8bya@...> wrote:
GE gentlemen. I was wondering if someone could direct me to some example
images, or a site showing how others have mounted their 10 GHz off-set
dish to a 2" OD mast. I would like to incorporate elevation control on
this version using a linear actuator. My dish is ~26" and a typical
"Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone
has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and
all those fun 70-90 MPH wind catastrophes so I am looking for a robust
design. Here are some images showing different elements of what I have.
I also included some images of where I "roughed in" my I0JXX feed based
on where the original LNB intersected the feed arm. I can supply
additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.








Off-Set Dish Mounting Ideas

Gedas
 

GE gentlemen. I was wondering if someone could direct me to some example images, or a site showing how others have mounted their 10 GHz off-set dish to a 2" OD mast. I would like to incorporate elevation control on this version using a linear actuator. My dish is ~26" and a typical "Dish Networks type".

I am hoping that rather me reinventing the wheel from scratch someone has a robust design I can borrow from.

Here at my QTH we get tornado's, straight line winds, micro bursts and all those fun 70-90 MPH wind catastrophes so I am looking for a robust design. Here are some images showing different elements of what I have. I also included some images of where I "roughed in" my I0JXX feed based on where the original LNB intersected the feed arm. I can supply additional images upon request. Thank you sincerely.

https://drive.google.com/file/d/1C2UmUqv0ViyhsdAEZB0X4A9NtkhmlBB8/view?usp=sharing

https://drive.google.com/file/d/1B7A67jX8GpYFCwvLEBYs02JbBetIE4u_/view?usp=sharing

https://drive.google.com/file/d/15pOyUdJBzG8DDsdwl98jSwxZRGTXHL1m/view?usp=sharing

https://drive.google.com/file/d/1CP5kxlQLsarEPm4AJgPXnYKYzoz5qJBr/view?usp=sharing

https://drive.google.com/file/d/1cqWxkAA-N7pTOvHRxUsx8TlXJ4_BkyK-/view?usp=sharing

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.


Re: RS

Dave - G4RQI
 

Hello John

Thanks for the QSO on 3cm yesterday… 

73 David


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of John Lemay <john@...>
Sent: Saturday, August 21, 2021 10:41:11 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] RS
 

Hello David

 

There’s certainly a lot of rain around today, although so far Essex is living up to its reputation and is dry.

 

I’m still learning about RS propagation, but my feeling is that with blanket coverage the prospects of RS are quite limited. But don’t let me put you off, and I’ll take a listen to beacons later and loiter on ‘KST if it looks promising.

 

Regards

 

John G4ZTR

 

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Dave - G4RQI
Sent: 20 August 2021 18:58
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] RS

 

Hello...

 

There’s quite a bit rain about tomorrow so anyone around in the afternoon on 10Ghz?

 

I’ll log into KST when I’m about

 

David – G4RQI IO93IR

Sent from Mail for Windows

 


Re: GB3GCT o 10368.935MHz

Paul G8AQA
 

As with any plant they need harvesting.

Paul G8AQA

On 22/08/2021 13:03, Neil Smith G4DBN wrote:
GCT was a decent RS signal again here in IO93 last night, despite the direct path being totally blocked by trees. I'm taking careful measurements to see which trees I need to fell to open up the direct path.  My chum had a look, sucked his teeth, and muttered "all of them...."

Neil G4DBN


On 22/08/2021 11:32, Dave G1EHF via groups.io wrote:
Thanks for the report John. Looking at the beacon site I'm not too surprised by your observations. The location is a local high spot but shielded to the North and South by the Berkshire Downs and Hannington/Walbury Hills respectively. I've attached an area coverage plot from Mike G0MJW's Path Profile software, which illustrates the situation nicely. Much better propagation East/West along the Kennet valley. A little rain probably helps the signal over the hills significantly. 73, Dave G1EHF








Virus-free. www.avg.com


Re: GB3GCT o 10368.935MHz

Neil Smith G4DBN
 

GCT was a decent RS signal again here in IO93 last night, despite the direct path being totally blocked by trees. I'm taking careful measurements to see which trees I need to fell to open up the direct path.  My chum had a look, sucked his teeth, and muttered "all of them...."

Neil G4DBN

On 22/08/2021 11:32, Dave G1EHF via groups.io wrote:
Thanks for the report John. Looking at the beacon site I'm not too surprised by your observations. The location is a local high spot but shielded to the North and South by the Berkshire Downs and Hannington/Walbury Hills respectively. I've attached an area coverage plot from Mike G0MJW's Path Profile software, which illustrates the situation nicely. Much better propagation East/West along the Kennet valley. A little rain probably helps the signal over the hills significantly. 73, Dave G1EHF


Re: GB3GCT o 10368.935MHz

John Fell
 

Hi Dave ,
Yes the path to GB3GCT is heavily obstructed in my direction , 37.2 degrees from me at 84km .

I have been surprised at the extent of RS returns from virtually all round the compass - far more frequent , so far  , than I observe from most other "local" beacons .

I have found peaks raising the dish EL by upto 7 degrees .This has taken near noise floor signal components to fully readable , non-RS "loud" levels - probably T cells at this time of year .
At other times raising the EL has had no effect - probably low density , light rain.

It will be interesting to see the effects with the standard "right kind of Rain" during the back end of the year .

Thank you and the Newbury Club for setting up this valuable resource .

73
John
G0API


Re: Balun for push-pull

Paul Randall G3NJV
 

Peter,  this is something I have an interest in,  would it be possible for you to send me that article as well?
Best 73
Paul G3NJV






-------- Original message --------
From: "Peter G3SMT via groups.io" <peter.torry@...>
Date: 17/08/2021 15:51 (GMT+00:00)
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Balun for push-pull

Will copy it and send it to you direct hopefully this evening.

73

Peter   G3SMT


On 17/08/2021 14:34, Andy G4JNT wrote:
Unfortunately my Dubii don't go back that far;  only to 2013, so the full article, explaining the matching operation is not to be found.
Is Dubus downloadable anywhere ?



On Tue, 17 Aug 2021 at 14:19, Peter G3SMT via groups.io <peter.torry=talktalk.net@groups.io> wrote:

I think that W6PQL utilised the original design by F1TE and F6BKI that was published in Dubus some ten to twelve years ago and in Technik XI.  Also described was a suitable 50MHz low pass filter.

73

Peter  G3SMT



On 17/08/2021 13:41, Andy G4JNT wrote:
NO, studied it a bit closer
The W6PQL design is 1:4.
So 1kW plus from 50V
Crafty bit of coax arranging there



On Tue, 17 Aug 2021 at 13:26, Andy Talbot <andy.g4jnt@...> wrote:

Just looking at the even weirder arrangement given in https://www.w6pql.com/1kw_6_meter_amplifier.htm . Scroll down to the bottom for the diagram.   That has a cross coupled set of twin lengths of coax which I think gives 1:9   bal-bal  then uses another single length for a 1:1 balun.
AFAICS the two twin lengths each transform an Rl which is then connected in series, and then in series with another Rl at the devices themselves.    Three lots of Rl, each with a third of the voltage across them is 9:1

Then comes the anachronism, that is a 1kW rated PA running from a 50V supply.   2 * 50² / 5.55Ω  = 900 Watts    so it's not a 1kW design 


--
Peter G3SMT

--
Peter G3SMT


Re: GB3GCT o 10368.935MHz

Dave G1EHF
 

Thanks for the report John. Looking at the beacon site I'm not too surprised by your observations. The location is a local high spot but shielded to the North and South by the Berkshire Downs and Hannington/Walbury Hills respectively. I've attached an area coverage plot from Mike G0MJW's Path Profile software, which illustrates the situation nicely. Much better propagation East/West along the Kennet valley. A little rain probably helps the signal over the hills significantly. 73, Dave G1EHF


Thin Sunstrates for Microstrip

Chris Bartram G4DGU <chris@...>
 

Apologies if I go into 'I've been though this before' mode ...

I spent a lot of time looking at, and designing a reproducable LNA (<1dB noise figure using my HP source and NFomenter) using a modern HEMT, and a 2W HMC952 amplifier nearly a decade ago. I made significant numbers of each. My substrate of choice was not teflon based like RO4003 - which can be shown to be money wasted for most applications at 10GHz - but another Rogers product, R2850. That was chosen because the simulated losses were VERY close to those for the teflon-based substrates, the material costs were much smaller, and because '2850 uses a low-loss dielectric other than Teflon, and can be processed using the same PTH techniques as FR4, the processing costs were also greatly reduced.

Much amateur design of microstrip circuitry uses substrate thicknesses which are rather greater than optimum, particularly at frequencies above 1.3GHz. That results in radiation losses. My designs of LNA and PA used 0.25mm 2850. I had the PCB processing performed by a UK based manufacturer, and the costs were not so much greater than for FR4.

Chris G4DGU


Re: Substrate thickness for 10 GHz

Greg - ZL3IX
 

JLC is the supplier I use but, as I said, they have an engineering surcharge for 0.4 mm PCBs, hence my question.


Re: Substrate thickness for 10 GHz

Robin Szemeti - G1YFG
 

And if you want really thin susbsrate jlc do 4 layer, with either 0.2mm top layer (jlc7638 layer stackup) or 0.1mm (jlc 2213 stackup) ... no use for the hmc pa chip, but useful for other microwave projects where thermal is not an issue.


On Sat, 21 Aug 2021, 14:12 Chris Ruddy MM0KOS via groups.io, <mm0kos=yahoo.co.uk@groups.io> wrote:

Hi Greg

 

JLC PCB does boards of both 0.4 and 0.6. Ive always had a great service form them but be selective on the postage to keep your costs down

 

Chris MM0KOS

 

Sent from Mail for Windows

 

From: Greg - ZL3IX
Sent: 21 August 2021 07:17
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Substrate thickness for 10 GHz

 

I've now completed my 10 GHz transverter and am starting on an LNA and PA. For the transverter I used PCBs with a 0.8 mm FR4 substrate and, apart from the 1 dB per inch track loss, it seemed to work out well. I have been thinking of using a thinner substrate for the LNA and PA, to minimise both the inductance and the thermal resistance of the vias. I have looked at both 0.4 mm and 0.6 mm substrates but the supplier I have been using puts a heavy engineering charge on to the 0.4 mm boards, resulting in a $50 + cost, compared with just $2 for the 0.6 mm option.

Does anyone have any opinion about the use of 0.6 mm vs 0.4 mm substrates in this application? Issues are obviously via inductance on the FET source connections that will affect the noise figure, and the via thermal conductivity under the paddle of the HMC952 device. The latter needs to lose about 8 W of heat.

73, Greg, ZL3IX

 


--
Robin Szemeti - G1YFG

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