Date   

WA5VJB 850-6500MHz LPY antennas

SAM JEWELL
 

Folks,
I have a received a few more of these from Kent.
A few of you had expressed interest in buying one, way back....... I am sorry, but I have mislaid the 'waiting' list.
In the UK they are £10 each with the SMA elbow/angle connector.


Please contact me, with location, for shipping cost.

73 de Sam, G4DDK


Re: Bell Hill Beacons

Neil Smith G4DBN
 

I had a close look last night at the local terrain map just now and that explains it, KBQ has a much better shot in this direction. I'm seeing KBQ now via rainscatter, but it is only just there. I'll have a closer look for SCX next time there is a decent scatterpoint, and have a harder look for plane scatter.

Ta, Neil

On 10/01/2021 20:16, Andy G4JNT wrote:
That is because, Neil, you are on the bad bearing from 'SCX in line with teh ridge.  Bearing to you, 16°  assuming you are IO93NR
The site is on top of a narrow ridge of more or less equal height, that runs for 2km on a roughly 30 degree bearing, and there's a lump of high ground slightly to the W of that which I thinks knocks you out.   So anyone within 10° of that bearing is not going to get the benefit of its otherwise good siting. Especially as we had to lower the mast last year when decent guys were no longer possible  Take off is excellent to the East and West.


Re: Bell Hill Beacons

Andy G4JNT
 
Edited

That is because, Neil, you are on the bad bearing from 'SCX in line with teh ridge.  Bearing to you, 16°  assuming you are IO93NR
The site is on top of a narrow ridge of more or less equal height, that runs for 2km on a roughly 30 degree bearing, and there's a lump of high ground slightly to the W of that which I thinks knocks you out.   So anyone within 10° of that bearing is not going to get the benefit of its otherwise good siting. Especially as we had to lower the mast last year when decent guys were no longer possible  Take off is excellent to the East and West.





On Sat, 9 Jan 2021 at 23:18, Neil Smith G4DBN <neil@...> wrote:

I've never understood why is it very rare for me to hear SCX on 3cm, despite hearing the slightly more distant KBQ frequently, about 8 degrees further west and 343 km away.  Path loss appears to be slightly better from SCX. Main difference is that the first obstacle towards SCX is 76km away, and it is a rounded hill rather than the closer and sharper hill 45km away on the path to KBQ.

I think I've only seen SCX via tropo twice, in September 2020. Before that, a few times on rainscatter Eight spots in all.  Contrast with KBQ, only 10km further away, which I've spotted 176 times.  I've listened for SCX just as often. GB3SEE is behind my trees, and I've only seen it a dozen times, but GB3PKT is a regular at a mere 252 km, spotted 120 times, but it was off for a fair slab of time.

I don't even hear SCX via plane scatter, not that there are many planes any more! Reflections from KBQ arrive regularly, so it must be something particularly absorbent in South Yorks or Notts.

Neil G4DBN


On 09/01/2021 21:22, Andy G4JNT wrote:
Yes, on your bearing of 35° from BH, it's unfortunate you're directly in line with the ridge and get no benefit of its being high up on a hill.



On Sat, 9 Jan 2021 at 19:25, neil whiting <neil@...> wrote:
Hi Andy,

I used to use these beacons regularly to check my systems on 2320/3400/5760MHz as I could hear
them almost all the time.
However since the tower height was reduced I can't hear them any more unless conditions are really good
- maybe 5 times a year? A real shame. I'm surprised the height has made so much difference.

73,
Neil  G4BRK

On Sat, 9 Jan 2021 at 11:22, Andy G4JNT <andy.g4jnt@...> wrote:
No,  Don't panic - they're all running OK :-)

Just posting to say Thank You to those who have made donations over the last few months towards the upkeep of these bacons - you know who you are.

If you regularly monitor these beacons from Bell Hill in Dorset,  LOC. IO80UU59  , then please consider making a donation to their upkeep and site rental.  With rally stands non-operational nowadays, the easiest way is to go to http://www.g4jnt.com/SCRBG/donate/index.html and hit the big yellow button.  Or a cheque to me QTHR.

For info.   The beacons are:
  GB3SCS 2320.905    JT4G
  GB3SCF 3400.905,   JT65C
  GB3SCC 5760.905,   JT4G
  GB3SCX 10368.905  JT4G
  GB3SCK 24048.905  JT4G
  GB3SCQ 47088.905 

All except the two highest frequency ones are GPS Locked to within a few Hz of nominal.




Re: SSB - Electronic SP-23 Preamp

mike G6TRM
 


Hi, Email sent direct
 
73
 
Mike G6TRM

----- Original Message -----
Sent: Sunday, January 10, 2021 6:49 PM
Subject: [UKMicrowaves] SSB - Electronic SP-23 Preamp

I have a SP23MKII mats head preamp, its not working.

 

I wonder if anyone has a circuit for it with the component value, I suspect one of the 2 Gas Fet, but unsure on what they are, they seem to be the same possible MGF1302 but not 100% sure.

 

Does anyone have any information that may help. Its quite an old unit so is there a better replacement device available now?

 

Regards Anthony G7LRQ


Re: SSB - Electronic SP-23 Preamp

Chris Gill
 

image.png

Technical Data Receive Pre-Amplifier (declared)
^^^ MVV 1296 VOX SSB Electronic SP-23 SSB Electronic SP-23MKII ^^
Frequency Range 1240-1300 1250-1300 1250-1300
MHz
Noise figure typ. 0,8-1,2 1,5 1,5
dB
Amplification typ. 22 20 20
dB
Max. Power (SSB) 180 100 100
Watt
Max. Power (FM) 100 100 100
Watt
Insertion loss < 0,5 0,4 0,4
dB
Supply voltage 13,5 13,5 13,5
V
Power requirement ca. 200 400 400
mA
Mast diameter 56 58 58
mm
Connectors N N N
-
DC Connector RCA (chinch) PL-259 (UC1) PL-259 (UC1)
-
TX RX switching HF-VOX up to 100W
or PTT-controlled
HF-VOX up to 10W
or via DCW-2004 100W
HF-VOX up to 10W
or via DCW-2004 100W
-
Relay CX-120P CX-531N CX-531N  
1st stage MGF1302 MGF1302 MGF1302
-
2nd stage MSA0686 BFG91 ERA-5SM
-
  http://www.shf-elektronik.de http://www.ssb.de http://www.ssb.de
-
Price 239euro   329euro
-
Download Users manual + schematic diagram 3.5MB Schematic of SP23 152kB    



On Sun, 10 Jan 2021 at 18:49, Anthony Coldman via groups.io <anthony.coldman=ntlworld.com@groups.io> wrote:

I have a SP23MKII mats head preamp, its not working.

 

I wonder if anyone has a circuit for it with the component value, I suspect one of the 2 Gas Fet, but unsure on what they are, they seem to be the same possible MGF1302 but not 100% sure.

 

Does anyone have any information that may help. Its quite an old unit so is there a better replacement device available now?

 

Regards Anthony G7LRQ



--
Regards

Chris Gill

+447 806 339 442

Delvin House
g8eem.chris@...


Re: SSB - Electronic SP-23 Preamp

Rien Eradus PA0JME
 

Hi Anthony, maybe this helps a bit,

http://www.sp5xmu.pl/23cm_preamp/

73es Rien PA0JME

Op 10-1-2021 om 19:49 schreef Anthony Coldman via groups.io:

I have a SP23MKII mats head preamp, its not working.

 

I wonder if anyone has a circuit for it with the component value, I suspect one of the 2 Gas Fet, but unsure on what they are, they seem to be the same possible MGF1302 but not 100% sure.

 

Does anyone have any information that may help. Its quite an old unit so is there a better replacement device available now?

 

Regards Anthony G7LRQ


Re: not hearing 13cm GB3MHz anymore

Rien Eradus PA0JME
 

Yes, but the tower is just some 250m away hi, wil try to test with a local station in Belgium tomorrow at 25km

73es Rien

Op 10-1-2021 om 18:15 schreef John Fell:

Well if the spurious levels are normal amplitude , this suggests your RX is probably ok and maybe a lump of this freezing fog across the Sea is blocking your signals from UK ?

73
John
G0API

On Sun, 10 Jan 2021 at 16:48, Rien Eradus PA0JME <pa0jme1952@...> wrote:
Thanks for the info John, I know condx were bad but normally it recovers quickly or there is the occasional plane reflection, but now nothing at all but for the spurious noise from telephone towers.
73 es Rien PA0JME


SSB - Electronic SP-23 Preamp

Anthony Coldman
 

I have a SP23MKII mats head preamp, its not working.

 

I wonder if anyone has a circuit for it with the component value, I suspect one of the 2 Gas Fet, but unsure on what they are, they seem to be the same possible MGF1302 but not 100% sure.

 

Does anyone have any information that may help. Its quite an old unit so is there a better replacement device available now?

 

Regards Anthony G7LRQ


Obsolete Suhner Connectors ...

Chris Bartram G4DGU
 

Hello All,

I've been going through my 'real junk' boxes getting rid of the real dross of ages, and have found some NIB (new in bag, in this case) Suhner N Jacks which I can't identify. They are not in the current Suhner literature.

The part number is 21N 50-12-101/003. The connectors look as though they are designed for a heliax (using that term very loosely!) - but which one? Does anyone have an old Suhner catalogue which refers to them?

73

Chris G4DGU


Re: not hearing 13cm GB3MHz anymore

John Fell
 

Well if the spurious levels are normal amplitude , this suggests your RX is probably ok and maybe a lump of this freezing fog across the Sea is blocking your signals from UK ?

73
John
G0API

On Sun, 10 Jan 2021 at 16:48, Rien Eradus PA0JME <pa0jme1952@...> wrote:
Thanks for the info John, I know condx were bad but normally it recovers quickly or there is the occasional plane reflection, but now nothing at all but for the spurious noise from telephone towers.
73 es Rien PA0JME


Re: not hearing 13cm GB3MHz anymore

Rien Eradus PA0JME
 

Thanks for the info John, I know condx were bad but normally it recovers quickly or there is the occasional plane reflection, but now nothing at all but for the spurious noise from telephone towers.
73 es Rien PA0JME


Re: not hearing 13cm GB3MHz anymore

John Quarmby
 

I have just checked the 13cm GB3MHZ beacon and it looks like there is a fault, so I have remotely switched it off for now. As access to the site is not permitted at present, it may be a while before it can return. I will post again when there is news.

73

John G3XDY

On 10/01/2021 11:30, Rien Eradus PA0JME wrote:
Hi all, normally I try to monitor the GB3MHZ beacons (currently 23, 13 and 9cm) which present a good condx indication.
The beacons are roughly 300km distance from my station.
The past few days condx we very bad due to rain and weather.
Weather has now improved and the signal of 23cm beacon has returned,albeit about 10 dB weaker than normal.
9cm is not audible nor is PI7RTD at about 80km distance, could be the transverter up in the mast.
My HP8672 generator can be heard though.
The same situation is true for 13 cm but normally the PI4 signal of GB3MHZ is around -13dB SNR, so with bad condx there is room to about -27dB SNR.
The past days nothing is received so I wonder if the problem is on my side but asking around gives the same picture.
The question remains is the beacon still on air?
Best regards Rien PA0JME

Virus-free. www.avast.com


Re: not hearing 13cm GB3MHz anymore

John Fell
 

Rein,
The conditions have been very poor across the uwave bands for some weeks now .
Today I have 50m visibility fog layer locally with a blocked High @ 1025mB .Would expect some enhancements but nothing - even sub-normal.
I would advise waiting before taking down any RF kit on your mast .

Best 73
John
G0API
IO80XS77JR 

On Sun, 10 Jan 2021 at 11:30, Rien Eradus PA0JME <pa0jme1952@...> wrote:
Hi all, normally I try to monitor the GB3MHZ beacons (currently 23, 13 and 9cm) which present a good condx indication.
The beacons are roughly 300km distance from my station.
The past few days condx we very bad due to rain and weather.
Weather has now improved and the signal of 23cm beacon has returned,albeit about 10 dB weaker than normal.
9cm is not audible nor is PI7RTD at about 80km distance, could be the transverter up in the mast.
My HP8672 generator can be heard though.
The same situation is true for 13 cm but normally the PI4 signal of GB3MHZ is around -13dB SNR, so with bad condx there is room to about -27dB SNR.
The past days nothing is received so I wonder if the problem is on my side but asking around gives the same picture.
The question remains is the beacon still on air?
Best regards Rien PA0JME


not hearing 13cm GB3MHz anymore

Rien Eradus PA0JME
 

Hi all, normally I try to monitor the GB3MHZ beacons (currently 23, 13 and 9cm) which present a good condx indication.
The beacons are roughly 300km distance from my station.
The past few days condx we very bad due to rain and weather.
Weather has now improved and the signal of 23cm beacon has returned,albeit about 10 dB weaker than normal.
9cm is not audible nor is PI7RTD at about 80km distance, could be the transverter up in the mast.
My HP8672 generator can be heard though.
The same situation is true for 13 cm but normally the PI4 signal of GB3MHZ is around -13dB SNR, so with bad condx there is room to about -27dB SNR.
The past days nothing is received so I wonder if the problem is on my side but asking around gives the same picture.
The question remains is the beacon still on air?
Best regards Rien PA0JME


Re: Bell Hill Beacons

Dave
 

Hello Neil,
I have the same problem with GB3FNY on 10ghz which has been heard twice and F5ZGV (478km) once only on 10ghz.
I can’t hear GB3MCB at all at Haytor as the granite hill is so high despite it being relatively near. 
73
Dave G4GLT.



On 9 Jan 2021, at 23:18, Neil Smith G4DBN <neil@...> wrote:



I've never understood why is it very rare for me to hear SCX on 3cm, despite hearing the slightly more distant KBQ frequently, about 8 degrees further west and 343 km away.  Path loss appears to be slightly better from SCX. Main difference is that the first obstacle towards SCX is 76km away, and it is a rounded hill rather than the closer and sharper hill 45km away on the path to KBQ.

I think I've only seen SCX via tropo twice, in September 2020. Before that, a few times on rainscatter Eight spots in all.  Contrast with KBQ, only 10km further away, which I've spotted 176 times.  I've listened for SCX just as often. GB3SEE is behind my trees, and I've only seen it a dozen times, but GB3PKT is a regular at a mere 252 km, spotted 120 times, but it was off for a fair slab of time.

I don't even hear SCX via plane scatter, not that there are many planes any more! Reflections from KBQ arrive regularly, so it must be something particularly absorbent in South Yorks or Notts.

Neil G4DBN


On 09/01/2021 21:22, Andy G4JNT wrote:
Yes, on your bearing of 35° from BH, it's unfortunate you're directly in line with the ridge and get no benefit of its being high up on a hill.



On Sat, 9 Jan 2021 at 19:25, neil whiting <neil@...> wrote:
Hi Andy,

I used to use these beacons regularly to check my systems on 2320/3400/5760MHz as I could hear
them almost all the time.
However since the tower height was reduced I can't hear them any more unless conditions are really good
- maybe 5 times a year? A real shame. I'm surprised the height has made so much difference.

73,
Neil  G4BRK

On Sat, 9 Jan 2021 at 11:22, Andy G4JNT <andy.g4jnt@...> wrote:
No,  Don't panic - they're all running OK :-)

Just posting to say Thank You to those who have made donations over the last few months towards the upkeep of these bacons - you know who you are.

If you regularly monitor these beacons from Bell Hill in Dorset,  LOC. IO80UU59  , then please consider making a donation to their upkeep and site rental.  With rally stands non-operational nowadays, the easiest way is to go to http://www.g4jnt.com/SCRBG/donate/index.html and hit the big yellow button.  Or a cheque to me QTHR.

For info.   The beacons are:
  GB3SCS 2320.905    JT4G
  GB3SCF 3400.905,   JT65C
  GB3SCC 5760.905,   JT4G
  GB3SCX 10368.905  JT4G
  GB3SCK 24048.905  JT4G
  GB3SCQ 47088.905 

All except the two highest frequency ones are GPS Locked to within a few Hz of nominal.




Re: Slew drives from China

Conrad, PA5Y
 

This company are very friendly to amateurs, I have bought a combination SVH7 7 inch AZ/EL drive from them.

 

The product is excellent.

 

www.coresundrive.com

 

I know that Paul W2HRO imports many SVH3 drives from them, these are fine for 3.7m dishes and thee are a good number in use.

 

http://www.coresundrive.com/en/product/Standard/2019/0802/157.html

 

Highly recommended.

 

73

 

Conrad PA5Y

 

 

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Bob Lockley VK6KW via groups.io
Sent: 10 January 2021 04:46
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Slew drives from China

 

This will open the door… looks like they cater for everyone.

https://www.slew-bearing.com/Single-Row-Ball-Internal-Gear-Slewing-Ring-for-Combination-Sewer-Cleaner-pd48770905.html

73,

Bob VK6KW.

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Dave Cawley G4IUG
Sent: Saturday, January 09, 2021 10:17 PM
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Slew drives from China

 

 

 

Hi Mike

 

Can you give me a link please ?

 

73  Dave  G4IUG


Re: Slew drives from China

Bob Lockley VK6KW
 

This will open the door… looks like they cater for everyone.

https://www.slew-bearing.com/Single-Row-Ball-Internal-Gear-Slewing-Ring-for-Combination-Sewer-Cleaner-pd48770905.html

73,

Bob VK6KW.

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Dave Cawley G4IUG
Sent: Saturday, January 09, 2021 10:17 PM
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Slew drives from China

 

 

 

Hi Mike

 

Can you give me a link please ?

 

73  Dave  G4IUG


Re: Bell Hill Beacons

Neil Smith G4DBN
 

I've never understood why is it very rare for me to hear SCX on 3cm, despite hearing the slightly more distant KBQ frequently, about 8 degrees further west and 343 km away.  Path loss appears to be slightly better from SCX. Main difference is that the first obstacle towards SCX is 76km away, and it is a rounded hill rather than the closer and sharper hill 45km away on the path to KBQ.

I think I've only seen SCX via tropo twice, in September 2020. Before that, a few times on rainscatter Eight spots in all.  Contrast with KBQ, only 10km further away, which I've spotted 176 times.  I've listened for SCX just as often. GB3SEE is behind my trees, and I've only seen it a dozen times, but GB3PKT is a regular at a mere 252 km, spotted 120 times, but it was off for a fair slab of time.

I don't even hear SCX via plane scatter, not that there are many planes any more! Reflections from KBQ arrive regularly, so it must be something particularly absorbent in South Yorks or Notts.

Neil G4DBN


On 09/01/2021 21:22, Andy G4JNT wrote:
Yes, on your bearing of 35° from BH, it's unfortunate you're directly in line with the ridge and get no benefit of its being high up on a hill.



On Sat, 9 Jan 2021 at 19:25, neil whiting <neil@...> wrote:
Hi Andy,

I used to use these beacons regularly to check my systems on 2320/3400/5760MHz as I could hear
them almost all the time.
However since the tower height was reduced I can't hear them any more unless conditions are really good
- maybe 5 times a year? A real shame. I'm surprised the height has made so much difference.

73,
Neil  G4BRK

On Sat, 9 Jan 2021 at 11:22, Andy G4JNT <andy.g4jnt@...> wrote:
No,  Don't panic - they're all running OK :-)

Just posting to say Thank You to those who have made donations over the last few months towards the upkeep of these bacons - you know who you are.

If you regularly monitor these beacons from Bell Hill in Dorset,  LOC. IO80UU59  , then please consider making a donation to their upkeep and site rental.  With rally stands non-operational nowadays, the easiest way is to go to http://www.g4jnt.com/SCRBG/donate/index.html and hit the big yellow button.  Or a cheque to me QTHR.

For info.   The beacons are:
  GB3SCS 2320.905    JT4G
  GB3SCF 3400.905,   JT65C
  GB3SCC 5760.905,   JT4G
  GB3SCX 10368.905  JT4G
  GB3SCK 24048.905  JT4G
  GB3SCQ 47088.905 

All except the two highest frequency ones are GPS Locked to within a few Hz of nominal.




4 Foot Prime Focus Dish

Adrian G4UVZ
 

4 Foot Fibreglass Prime Focus dish up for grabs!

Dish is substantial with metalised reflective surface complete with 4 fibreglass stays to support LNB etc

Free to a good home but would appreciate a small donation to GB3KBQ running costs!

Collection from TA3. M5 Junction 25 ..please PM if this is of interest

G4UVZ


Re: Re elevation on a dish

Dave
 

Hi John,
The 12 food dish sounds amazing. It must have had a very narrow focus indeed. It was good to know that a metre of waveguide is still good for a terrestrial system. I am looking now at the mechanics and hopefully will have a system to go on a trailer for the summer with a dish above people’s heads. 
I guess we are spoilt these days with the modules from DB6NT, when in days gone by it was a lot harder to get a decent system together. 
Anyway thanks again for all the details .
73
Dave G4GLT. 

On 8 Jan 2021, at 14:13, John Fell <john.g0api@...> wrote:


Hi Dave ,
I had a 20W TWT based system up this mast for over 20 years before moving on to use bits of it for 10GHz EME at G4RFR .

The first G to G contact on 10GHz (CW) used the TVTR - 1994 between G4RFR and G3WDG , using 12 Ft prime focus 0.43f/D dish at our end.

The TVTR was quite a load for my 30Ft Western Ulimast and restricted other band antenna deployment a bit .....feeding all TWT rails up rotator style multicore cables ......
My TVTR used original G3WDG modules with a modified 4 port WG16 on its front end , with the 2 stages of LNA directly on the RX port and TWT output on the TX port .The feed was a G3PHO type WG 16 flanged and feeding the 4 port switch via EW90 elliptical waveguide .Probably had about 1 m total between the feed and the front end LNA .
For tropo use this still represents a reasonable insertion loss . You can easily make ur own EW90 flanges to marry standard WG16 flanged ports .
Form the required bends into the EW90 - using gentle bends by hand /vice.

A 10W system at the dish will form a potent terrestrial system , but do spend the time to Engineer the housing to prevent condensation .An inverted bucket format is good as it allows airflow and if you take all services in via the open end rain tends to stay out .( worked a few with 10W TWT last year on the 12Ft dish - on 10GHz CW ) . The 200W TWT makes for louder echoes though .

From home I am only operational on RX on 10GHz , but having £10 LNBs and GPS reference locking makes it a potent and cheap thing to do .

73
John
G0API

On Fri, 8 Jan 2021 at 11:33, Dave via groups.io <davidnewman55=icloud.com@groups.io> wrote:
Hello John,
Thanks very much indeed for photos of your system. Yes, I take your point about spacing the dish far away enough to get 30 degrees of elevation. I am torn between using a  waveguide feed or preamp at the feedpoint.
I will look at the limits of the Jack very carefully in the workshop as you suggested. 
If your system has lasted for so long it must be very rugged and well constructed. 
Thanks again for all the pointers.
73
Dave G4GLT. 

On 8 Jan 2021, at 10:55, John Fell <john.g0api@...> wrote:


Hi Dave ,
Had to wait for the frost to lift to take these pics .
My masthead 60cm dish and Elevation system .

18" jack used with base end pivot made from 3" exhaust clamp around the standard Scaf pole mast extension above KR600 inside cage support ( just below bottom of pic).Extra large clamp allows one leg of U bolt to be fitted with a turned alum sleeve spacer to take the eye of the base balljoint of the jack.Also allows positional adjustment to set up desired stroke/maximum dish travel..

Top end of jack fits onto a welded pivot bolt attached to underside of a 2 x 1" steel hollow section , welded or bolted to a steel stand-off plate that has a steel hinge at the mast end .The other end of the hinge is welded to a steel Scaf clamp , which again can be adjusted to setup the final geometry .

The dish is mounted on 1.25" dimeter steel tube that came with it - in this case it is a 90 degree bent item so that is why the 2X1" hollow section is used to offset the dish tube and put the vertical load thrust on the centre line of the vertical mast .Room to add masthead PA/front end housings just behind the dish , without adding much loading to the feed arm etc .

You will notice the system puts the offset dish well forward offset to the mast - this allows the top rim of the dish to travel to an effective 30 degrees of Elevation .
That allows pointing at QO100 and well above ground noise sources for Sun noise  measurements and I have decoded DL0SHF several times over last few years .Other antennas on mast above are positioned to offset the dish system , again putting the vertical loading equally about the rotator cage .

The small box on a standoff 1"x1/8" aluminium flat bar just in front and below dish base  is housing a G4JNT AZ/EL digital sensor .

Which ever system you build make sure the jack is adjusted so its internal limit switches limit the travel within limits that protect the dish - I managed to fold this dish at the top with 12V supply and the only thing I noticed was a sudden rise in ground noise !

After 30+ years up the mast the only thing that needed replacement was the jack ( running leadscrew nut fractured ) -  the light coloured cylinder on the jack is an old aluminium Dow Corning Vacuum oil can - this covers the top end jack seal to prevent rain getting in when/if the seal cracks - smother all surfaces in Waxoil ....

73
John
G0API

On Thu, 7 Jan 2021 at 17:03, Dave via groups.io <davidnewman55=icloud.com@groups.io> wrote:
Hello,
I am adding elevation on a dish for tropo only (not EME) and wondered if anyone has a photo of the mechanics of it, preferably with some sort of hinge . I have an actuator which has a stroke length of 4 inches. I think the lower part of the dish will have to be pushed outwards.
73
Dave G4GLT.





<DSCF7244.JPG>
<DSCF7245.JPG>

2581 - 2600 of 62926