Date   

Re: COAXIAL CABLE LMR400

ian hope (2E0IJH)
 

We use drums and drums of a Clone from WIFI antennas, it uses slightly larger centre pin than Rg213, we buy plugs from M0MAT on ebay, 
 
https://www.wifi-antennas.co.uk/hdf400-coaxial-cable-100m-drum
 
It is quite stiff, but not as bad as LDF, you can a flexible version for rotator loops
 
Hope that helps 
 
Ian
M5IJH

 
 
Sent: Saturday, May 08, 2021 at 9:26 PM
From: "Martin" <gw3xjq@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] COAXIAL CABLE LMR400
Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      


Re: COAXIAL CABLE LMR400

John Quarmby
 

There are a lot of clones around, some better than others, in my experience it is best to avoid eBay, having encountered a clone where the aluminium shield did not enclose the whole circumference of the dielectric. If you are including a turning loop at the top of the tower then go for LMR400UF which has a stranded copper inner conductor and will last longer, but it does have slightly higher loss.

I have used Gigatronix to make up cables with crimp connectors and suitable strain relief, using their LBC400ExtraFlex equivalent. After 6 years I am just about to replace one of the masthead cables as the inner of the N socket at the top is now badly worn from changing antennas every week, all their other coax jumpers up there are still going strong.

They have a useful ordering tool where you can try various connector and cable options:

https://www.gigatronix.co.uk/cabulator/coaxial/cable-type

73

John G3XDY

On 08/05/2021 20:26, Martin wrote:
Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      

Virus-free. www.avast.com


COAXIAL CABLE LMR400

Martin
 

Could I ask for some information on LMR 400 coaxial cable from anyone who has used it and how it turns out in practise. 
I gather from what I have read, that its good quality and fairly low loss when compared with the other 10 mm approx. diameter cables. I am looking for something for use on 23 cms and will be using half inch LDF4-50A for the main run from shack to tower base and something more flexible from there on, around say another 45 feet. I will be running an LNA at the top and close to the Yagi.
I cannot see that it is available from the main amateur radio dealers and there is one commercial supplier who will only provide it in 100 m drums.  I am happy to invest a in this quantity, (for other purposes and bands) but not until I know more about the cable itself. Does it require special N series plugs and how flexible is it etc? Its available on eBay I think but again, reading seems to suggest there is some dubious quality cable being sold which is fake?      


Re: 6cm tests

militaryoperator
 

Whilst one may be lead to believe everything in the RF world is 50 ohms it often is not the case, With this in mind
i would suggest that when you take a modularised approached to making a front end that you don't connect up with random sma coax patch leads. Perhaps you haven't but i would strongly recommend just using sma barrel adaptors to connect things together.
cheers
Geoff
GI0GDP

Thanks  Geoff. Yes, I sat here one day and with a 10ghz tx and my power meter, first direct on tx then various sma leads I found quite a drop in power on some, as you say, not everything is equal. 

Yes, barrel used and as short as poss if lead needed. 

cheers, Ben G4BXD



Re: 6cm tests

geoffrey pike
 

Whilst one may be lead to believe everything in the RF world is 50 ohms it often is not the case, With this in mind
i would suggest that when you take a modularised approached to making a front end that you don't connect up with random sma coax patch leads. Perhaps you haven't but i would strongly recommend just using sma barrel adaptors to connect things together.
cheers
Geoff
GI0GDP

On Saturday, 8 May 2021, 15:17:21 BST, Neil Smith G4DBN <neil@...> wrote:


NLB-310 or NLB-400 have more gain, but still not a good noise figure (around 5dB).

https://www.mouser.co.uk/datasheet/2/412/lb_300_data_sheet-1504712.pdf

https://www.mouser.co.uk/datasheet/2/412/lb_400_data_sheet-1506836.pdf

Neil G4DBN

On 08/05/2021 14:49, Chris G0WUS wrote:

yes or even 3 pipe cap filter between em.

Google W1GHZ 6cm transverter

Chris G0WUS

On 08/05/2021 14:15, militaryoperator via groups.io wrote:


try ERA-1 maybe
Chris


only about 8db gain at 6Ghz, so maybe two in series?

Ben


Re: Astra Satellite

Michael Scott
 

Many thanks Luc, very useful!

73, Mike.

On 08/05/2021 16:43, Luc , on4aol wrote:
Or maybe on this site

http://frequencyplansatellites.altervista.org/Beacon-Telemetry_Europe-Africa-MiddleEast.html

73 Luc on4aol


Re: Astra Satellite

Luc , on4aol
 


Re: 6cm tests

Neil Smith G4DBN
 

NLB-310 or NLB-400 have more gain, but still not a good noise figure (around 5dB).

https://www.mouser.co.uk/datasheet/2/412/lb_300_data_sheet-1504712.pdf

https://www.mouser.co.uk/datasheet/2/412/lb_400_data_sheet-1506836.pdf

Neil G4DBN

On 08/05/2021 14:49, Chris G0WUS wrote:

yes or even 3 pipe cap filter between em.

Google W1GHZ 6cm transverter

Chris G0WUS

On 08/05/2021 14:15, militaryoperator via groups.io wrote:


try ERA-1 maybe
Chris


only about 8db gain at 6Ghz, so maybe two in series?

Ben
_._,_._,_



Re: 6cm tests

Chris G0WUS
 

yes or even 3 pipe cap filter between em.

Google W1GHZ 6cm transverter

Chris G0WUS

On 08/05/2021 14:15, militaryoperator via groups.io wrote:


try ERA-1 maybe
Chris


only about 8db gain at 6Ghz, so maybe two in series?

Ben


Re: 6cm tests

militaryoperator
 



try ERA-1 maybe
Chris


only about 8db gain at 6Ghz, so maybe two in series?

Ben


Re: 6cm tests

Chris G0WUS
 

try ERA-1 maybe

Chris


On 08/05/2021 12:42, militaryoperator via groups.io wrote:
oh yes Simon, but as many will say, its the fun of it !!!!!

I thought I';d better see if those SPF boards do work somewhere, on 2mtrs its 23db gain so I guess I'll not be throwing them away yet. Guess 6Ghz was asking a lot!

Tried some Avantek modules, marked 2.7 to 3.3Ghz 12v and they are good, 23db at 2.4 with 200mw o/p at 0dbm in. I must try and find a use for them. 

Ben. G4BXD




Subject: Re: [UKMicrowaves] 6cm tests

I had a similar experience yesterday on 13cm, LO ADF4351, mixer ADL5350, LNA SPF5189, bi-quad antenna, Sky 60cm dish. I could barely make out GB3FNM at 25km.

As this is my first attempt at microwave frequencies I don't really know what to expect. The path to FNM was nearly line of sight but not quite.

Still it's a start.

Simon
G0FCU.

On Sat, 8 May 2021, 10:19 militaryoperator via groups.io, <Military1944=aol.com@groups.io> wrote:
Well, that was a waste of several hours of my life. 

Tried using one of the SPF5189  devices into first a ADL5350 mixer and then a Anaren dbl bal mixer 2.5 to 10Ghz, using the ADF osc as the lo. I can see 5.760 from the sig gen on the SDRConsole with RSP2 but could not see OHM in B'ham but I was only using an LPA on its own.

I see ebay has some similar boards marked as upto 6ghz but does not state device, probably the same as above with a different printed cover! At £6.68 guess a punt will not kill me. 

Whilst all the stuff was out re-tried these supposed 1W amps for 2.4, RF2126 devices, what a croc. Best was 150mw o/p at 2.4 which rose to 300mw at 2.3, obviously, the matching etc is not right I guess. Pity, its a nice pcb but I guess I win a nice heatsink though. 

So, back to the drawing board. 

Ben. 


Re: 6cm tests

militaryoperator
 

oh yes Simon, but as many will say, its the fun of it !!!!!

I thought I';d better see if those SPF boards do work somewhere, on 2mtrs its 23db gain so I guess I'll not be throwing them away yet. Guess 6Ghz was asking a lot!

Tried some Avantek modules, marked 2.7 to 3.3Ghz 12v and they are good, 23db at 2.4 with 200mw o/p at 0dbm in. I must try and find a use for them. 

Ben. G4BXD




Subject: Re: [UKMicrowaves] 6cm tests

I had a similar experience yesterday on 13cm, LO ADF4351, mixer ADL5350, LNA SPF5189, bi-quad antenna, Sky 60cm dish. I could barely make out GB3FNM at 25km.

As this is my first attempt at microwave frequencies I don't really know what to expect. The path to FNM was nearly line of sight but not quite.

Still it's a start.

Simon
G0FCU.

On Sat, 8 May 2021, 10:19 militaryoperator via groups.io, <Military1944=aol.com@groups.io> wrote:
Well, that was a waste of several hours of my life. 

Tried using one of the SPF5189  devices into first a ADL5350 mixer and then a Anaren dbl bal mixer 2.5 to 10Ghz, using the ADF osc as the lo. I can see 5.760 from the sig gen on the SDRConsole with RSP2 but could not see OHM in B'ham but I was only using an LPA on its own.

I see ebay has some similar boards marked as upto 6ghz but does not state device, probably the same as above with a different printed cover! At £6.68 guess a punt will not kill me. 

Whilst all the stuff was out re-tried these supposed 1W amps for 2.4, RF2126 devices, what a croc. Best was 150mw o/p at 2.4 which rose to 300mw at 2.3, obviously, the matching etc is not right I guess. Pity, its a nice pcb but I guess I win a nice heatsink though. 

So, back to the drawing board. 

Ben. 


Re: 6cm tests

Andy G4JNT
 

Take a look at the datasheet for the SPF5189.   You'll see that although it is "specified" for use up to 4GHz, none of the RF specs that are listed of graphed are specified above 2.2GHz

The only indication of activity above 2.2GHz is seen in the " GMAX versus Frequency" curve on page 7 which suggests gain has dropped to ~ 8.5dB at 3.4GHz

Note also how in  " Typical RF Performance " on Page 2 of the DS, how the noise figure jumps from 0.91 at 2.1GHz to 0.98 at 2.2GHz

That may be a clue to why you are seeing poor performance; the NF may well be terrible at 3.4GHz and there's not much gain to overcome mixer loss




On Sat, 8 May 2021 at 12:24, G0FCU <simon@...> wrote:
I had a similar experience yesterday on 13cm, LO ADF4351, mixer ADL5350, LNA SPF5189, bi-quad antenna, Sky 60cm dish. I could barely make out GB3FNM at 25km.

As this is my first attempt at microwave frequencies I don't really know what to expect. The path to FNM was nearly line of sight but not quite.

Still it's a start.

Simon
G0FCU.

On Sat, 8 May 2021, 10:19 militaryoperator via groups.io, <Military1944=aol.com@groups.io> wrote:
Well, that was a waste of several hours of my life. 

Tried using one of the SPF5189  devices into first a ADL5350 mixer and then a Anaren dbl bal mixer 2.5 to 10Ghz, using the ADF osc as the lo. I can see 5.760 from the sig gen on the SDRConsole with RSP2 but could not see OHM in B'ham but I was only using an LPA on its own.

I see ebay has some similar boards marked as upto 6ghz but does not state device, probably the same as above with a different printed cover! At £6.68 guess a punt will not kill me. 

Whilst all the stuff was out re-tried these supposed 1W amps for 2.4, RF2126 devices, what a croc. Best was 150mw o/p at 2.4 which rose to 300mw at 2.3, obviously, the matching etc is not right I guess. Pity, its a nice pcb but I guess I win a nice heatsink though. 

So, back to the drawing board. 

Ben. 


Re: 6cm tests

G0FCU
 

I had a similar experience yesterday on 13cm, LO ADF4351, mixer ADL5350, LNA SPF5189, bi-quad antenna, Sky 60cm dish. I could barely make out GB3FNM at 25km.

As this is my first attempt at microwave frequencies I don't really know what to expect. The path to FNM was nearly line of sight but not quite.

Still it's a start.

Simon
G0FCU.

On Sat, 8 May 2021, 10:19 militaryoperator via groups.io, <Military1944=aol.com@groups.io> wrote:
Well, that was a waste of several hours of my life. 

Tried using one of the SPF5189  devices into first a ADL5350 mixer and then a Anaren dbl bal mixer 2.5 to 10Ghz, using the ADF osc as the lo. I can see 5.760 from the sig gen on the SDRConsole with RSP2 but could not see OHM in B'ham but I was only using an LPA on its own.

I see ebay has some similar boards marked as upto 6ghz but does not state device, probably the same as above with a different printed cover! At £6.68 guess a punt will not kill me. 

Whilst all the stuff was out re-tried these supposed 1W amps for 2.4, RF2126 devices, what a croc. Best was 150mw o/p at 2.4 which rose to 300mw at 2.3, obviously, the matching etc is not right I guess. Pity, its a nice pcb but I guess I win a nice heatsink though. 

So, back to the drawing board. 

Ben. 


6cm tests

militaryoperator
 

Well, that was a waste of several hours of my life. 

Tried using one of the SPF5189  devices into first a ADL5350 mixer and then a Anaren dbl bal mixer 2.5 to 10Ghz, using the ADF osc as the lo. I can see 5.760 from the sig gen on the SDRConsole with RSP2 but could not see OHM in B'ham but I was only using an LPA on its own.

I see ebay has some similar boards marked as upto 6ghz but does not state device, probably the same as above with a different printed cover! At £6.68 guess a punt will not kill me. 

Whilst all the stuff was out re-tried these supposed 1W amps for 2.4, RF2126 devices, what a croc. Best was 150mw o/p at 2.4 which rose to 300mw at 2.3, obviously, the matching etc is not right I guess. Pity, its a nice pcb but I guess I win a nice heatsink though. 

So, back to the drawing board. 

Ben. 


Re: QRP PA devices for 10 GHz

Neil Smith G4DBN
 

Price with tax, delivery duty paid was £40.60 each for ten-off from Digikey.  No need for an EAR declaration.

Neil G4DBN

On 07/05/2021 22:10, Neil Smith G4DBN wrote:

HMC952A looks reasonable at around £37 plus tax at Mouser and £34 at Digikey in 10-off Cheaper from Arrow/Richardson RFPD, but DK/Mouser deal with UK import VAT, saving customs fees. I just bought ten in case they decide to go on back order adn 52 week delivery, like some parts.

https://www.digikey.co.uk/product-detail/en/analog-devices-inc/HMC952ALP5GE/1127-3364-ND/5813138

https://www.mouser.co.uk/datasheet/2/609/HMC952A-972562.pdf

35 dBm saturated , P1dB 32 dBm, and over 30dB gain at 10368 MHz internally matched and with a power detector. Needs negative bias and interlocks for bias loss, overcurrent, and needs a temperature monitor. Power is +6V at 1400 mA quiescent and 2 A flat out.  The PCB needs to shift heat well, the pad is 3 x 3 mm and needs to lose 10 watts,  Thermal resistance is already pretty high, so cooling is a serious challenge, even if the PCB has lots of vias under that pad and it is soldered to a copper case or spreader.

There are still some gasfet devices around, but of the current crop of non-obsolete parts, this one looks to be best value. HMC487 is lower power, lower gain and double the price for no obvious benefit.

Neil G4DBN

On 07/05/2021 21:36, Greg - ZL3IX wrote:
We've recently seen a couple of posts on this group about higher power (and expensive) PA devices, but what are guys using for the lower powers, maybe 0.5 - 2W? Are there devices around for a more reasonable price? I'm making fair progress with my home brew transverter for 10 GHz, and the next stage will be to produce a little power on the band. ideas?
-- 
Neil
http://g4dbn.uk


Re: QRP PA devices for 10 GHz

Neil Smith G4DBN
 

HMC952A looks reasonable at around £37 plus tax at Mouser and £34 at Digikey in 10-off Cheaper from Arrow/Richardson RFPD, but DK/Mouser deal with UK import VAT, saving customs fees. I just bought ten in case they decide to go on back order adn 52 week delivery, like some parts.

https://www.digikey.co.uk/product-detail/en/analog-devices-inc/HMC952ALP5GE/1127-3364-ND/5813138

https://www.mouser.co.uk/datasheet/2/609/HMC952A-972562.pdf

35 dBm saturated , P1dB 32 dBm, and over 30dB gain at 10368 MHz internally matched and with a power detector. Needs negative bias and interlocks for bias loss, overcurrent, and needs a temperature monitor. Power is +6V at 1400 mA quiescent and 2 A flat out.  The PCB needs to shift heat well, the pad is 3 x 3 mm and needs to lose 10 watts,  Thermal resistance is already pretty high, so cooling is a serious challenge, even if the PCB has lots of vias under that pad and it is soldered to a copper case or spreader.

There are still some gasfet devices around, but of the current crop of non-obsolete parts, this one looks to be best value. HMC487 is lower power, lower gain and double the price for no obvious benefit.

Neil G4DBN

On 07/05/2021 21:36, Greg - ZL3IX wrote:
We've recently seen a couple of posts on this group about higher power (and expensive) PA devices, but what are guys using for the lower powers, maybe 0.5 - 2W? Are there devices around for a more reasonable price? I'm making fair progress with my home brew transverter for 10 GHz, and the next stage will be to produce a little power on the band. ideas?
_._,_._,_



Re: Narda attenuator

 

Here is one of the type you refer to: appears to have 6 attenuator sections, 5 pi and one T (for some reason!) 27 dB total attenuation, 10W, and works well up to 6GHz. The left end is marked "input". 

On Fri, May 7, 2021 at 01:01 PM, John Quarmby wrote:

A distributed attenuator of the type suggested by Claudio would certainly make the thermal design simpler and could be realised using thick film resistors on a BeO substrate. You could make a bidirectional version with graded sections at each end.

I had one of those nice 150W Narda attenuators but managed to blow it up, I do remember it being marked as containing BeO.

73

John G3XDY

On 07/05/2021 10:09, i2NDT via groups.io wrote:

good to know Andy!

I naively thought that high power uni-directional attenuators were a combination of several attenuators in series, such as a 3dB at the input followed by a 27dB, to distribute the thermal load on several devices.

Claudio

Virus-free. www.avast.com


QRP PA devices for 10 GHz

Greg - ZL3IX
 

We've recently seen a couple of posts on this group about higher power (and expensive) PA devices, but what are guys using for the lower powers, maybe 0.5 - 2W? Are there devices around for a more reasonable price? I'm making fair progress with my home brew transverter for 10 GHz, and the next stage will be to produce a little power on the band. ideas?


Re: 10 GHz 35W GaN PA devices arrived

David Law
 

I'll bring the dish, you bring the amp and we can listen to ourselves off the moon!

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