Date   

Re: 6cm rf?

militaryoperator
 

The data sheet from Skyworks does not give any thermal info and it may be that key down CW at 2W will overheat the junction.

6cm.jpg
160deg C Mark.


. if they work as advertised.  If they dont, send em back!
Mark GM4ISM


I doubt worth trying to send back to China. Still you get either a nice little project box or a nice heatsink depending on which you buy, hi. 

Ben,


Re: 6cm rf?

Mark GM4ISM
 

Ben

Both seem to use the same output device

The device is  designed for wideband data modes at 400mW. This requires high linearity, hence the typical single tone P1db of 34dBm (min is +30)

Efficiency at 26dBm is not great, probably better in CW mode but you've got to get quite a lot of heat out of a small area.

The data sheet from Skyworks does not give any thermal info and it may be that key down CW at 2W will overheat the junction.

In amateur use the TX duty cycle helps us and   it may be able to run at 2W  out  for typical QSOs, if on a good heat sink.  The 40dB gain module  will need to be bolted to one. We also don't often have high ambient temperature that may push the limits

So, with the usual caveats, if the devices are genuine and full spec and the board has been properly designed (thermally)  2W PEP is not  impossible without damage.

It is interesting that the second one  states 1W for the same device, perhaps being a little more conservative.

None of the vendors are saying how long the device will last at  the P1dB level key down...

Even at 1W these represent reasonable value for money... if they work as advertised.  If they dont, send em back!

Mark GM4ISM


On 20/05/2021 11:44, militaryoperator via groups.io wrote:
5G-6GHz One-Way Microwave RF Power Amplifier Module 40DB SBB5089+SE5004
( 114749899192 )

SE5004 1W Microwave Power Amplifier RF Power Amplifier 5.15GHz-5.85GHz 30DBm
( 114556927546 )

Did anyone try these? Both use the SE5004 which seems rated to 34dbm max, 

I'm guessing the first unit rated at 2W is 2 Chinese Watts. The second unit might just do it.

Probably get 1W out of first but it has more gain so smaller i/p needed I guess.

 Ben.

Virus-free. www.avg.com


Re: Norton Amplifiers

Conrad, PA5Y
 

That looks very useful Neil but a bit too much gain.

I am glad that you weren't dreaming because to dream of such things would be a little, dare I say, odd?

73

Conrad


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Neil Smith G4DBN via groups.io <neil@...>
Sent: 19 May 2021 20:43
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Norton Amplifiers
 
Note dreaming after all. Phew. This is the Appnote I vaguely recalled.
Looks like it is about the ZRL-700+ (and the other models)

https://www.minicircuits.com/appdoc/AN60-039.html

Neil G4DBN

On 19/05/2021 19:23, Conrad, PA5Y wrote:
> Could you be referring to the HELA10B dual monolithic amplifier? I have a pair of these on my 2-channel adaptive EME system. They are there to overcome splitter losses and give a bit of extra gain for the IQ+. The path for one channel is HELA10B (11db gain 2.5dB NF on 144) then a Band pass filter, then a 3dB hybrid splitter. One side feeds the IQ+ (used for the adaptive RX) and the other my transverter which is used a linear polarisation (either +/- 45 deg) channel with the K3S.  The whole system seems to work very well.
>
> I will try one on 432 but the noise figure is significantly higher on the 4 that I built.
>
> https://www.minicircuits.com/app/AN60-009.pdf
>
> You need a heatsink!
>







Re: Hi Speed Comparator operation

Rien Eradus PA0JME
 

https://www.analog.com/media/en/technical-documentation/data-sheets/lt1016.pdf

Op 20-5-2021 om 15:18 schreef Rien Eradus PA0JME via groups.io:

A bit further datasheet shows

Input Impedance and Bias Current

Input bias current is measured with the output held at 1.4V. As with any simple NPN differential input stage, the LT1016 bias current will go to zero on an input that is low and double on an input that is high. If both inputs are less than 0.8V above V, both input bias currents will go to zero. If either input exceeds the positive common mode limit, input bias current will increase rapidly, approaching several milliamperes at VIN = V+.

Op 20-5-2021 om 12:04 schreef G8ZHA via groups.io:
I have built a couple of W1GHz projects: a GPS locked 10MHz osillator and a 100MHz PLL board. Each of his circuits uses a LT1116 hi speed comparator to lift the oscilator signal up to 5V CMOS logic levels to feed the dividers.

On the 100MHz PLL PCB, there is a 3.3V osc, feeding a MC12080 Div by 10 prescaler, AC coupled into the non-inverting input ofthe LT1116. The inverting input is tied directly to ground. I can see a nice square wave signal into this pin, about 1.5V pk-pk, centered on 0V. The outputs, which are open circuit, are very distorted, see photos.

I thought that this may be because the signal is outside the common range of 0 - 2.5V for the LT1116, so I biased the input to the middle of the voltage range but was not successful.

Am I missing something obvious?

I also built the 10MHz version, which feeds the osc straight into the comparator. I hadn't got a LT1116, so used a LT1016 instead, which has a common mode input range of 1.25 tp 3.75V range. Again, I biased the input signal to the middle of the voltage range, but saw the same distored oyutput.

(in the UK, the LT1116 is not available from RS etc)

I am at a loss to understand what is going wrong.

Rich G*ZHA


Re: Hi Speed Comparator operation

Rien Eradus PA0JME
 

A bit further datasheet shows

Input Impedance and Bias Current

Input bias current is measured with the output held at 1.4V. As with any simple NPN differential input stage, the LT1016 bias current will go to zero on an input that is low and double on an input that is high. If both inputs are less than 0.8V above V, both input bias currents will go to zero. If either input exceeds the positive common mode limit, input bias current will increase rapidly, approaching several milliamperes at VIN = V+.

Op 20-5-2021 om 12:04 schreef G8ZHA via groups.io:

I have built a couple of W1GHz projects: a GPS locked 10MHz osillator and a 100MHz PLL board. Each of his circuits uses a LT1116 hi speed comparator to lift the oscilator signal up to 5V CMOS logic levels to feed the dividers.

On the 100MHz PLL PCB, there is a 3.3V osc, feeding a MC12080 Div by 10 prescaler, AC coupled into the non-inverting input ofthe LT1116. The inverting input is tied directly to ground. I can see a nice square wave signal into this pin, about 1.5V pk-pk, centered on 0V. The outputs, which are open circuit, are very distorted, see photos.

I thought that this may be because the signal is outside the common range of 0 - 2.5V for the LT1116, so I biased the input to the middle of the voltage range but was not successful.

Am I missing something obvious?

I also built the 10MHz version, which feeds the osc straight into the comparator. I hadn't got a LT1116, so used a LT1016 instead, which has a common mode input range of 1.25 tp 3.75V range. Again, I biased the input signal to the middle of the voltage range, but saw the same distored oyutput.

(in the UK, the LT1116 is not available from RS etc)

I am at a loss to understand what is going wrong.

Rich G*ZHA


Re: Hi Speed Comparator operation

Rien Eradus PA0JME
 

Hi I am not familiar with both devices but took a glance at de 1016's datasheet. It tells me that inputbias current is about 10uA.  If Vss is at ground there can be no bias current at all unless input consists of pnp pair. Maybe you have to lift both inputs a bit to allow for biascurrent to flow and decouple the inverted input. That is what the datasheet shows providing bias through a decoupled resistor from the output. Tieing a i/p to ground is never a good idea unless a device has both positive and negative supplies.

Best regards Rien PA0JME

Op 20-5-2021 om 12:04 schreef G8ZHA via groups.io:

I have built a couple of W1GHz projects: a GPS locked 10MHz osillator and a 100MHz PLL board. Each of his circuits uses a LT1116 hi speed comparator to lift the oscilator signal up to 5V CMOS logic levels to feed the dividers.

On the 100MHz PLL PCB, there is a 3.3V osc, feeding a MC12080 Div by 10 prescaler, AC coupled into the non-inverting input ofthe LT1116. The inverting input is tied directly to ground. I can see a nice square wave signal into this pin, about 1.5V pk-pk, centered on 0V. The outputs, which are open circuit, are very distorted, see photos.

I thought that this may be because the signal is outside the common range of 0 - 2.5V for the LT1116, so I biased the input to the middle of the voltage range but was not successful.

Am I missing something obvious?

I also built the 10MHz version, which feeds the osc straight into the comparator. I hadn't got a LT1116, so used a LT1016 instead, which has a common mode input range of 1.25 tp 3.75V range. Again, I biased the input signal to the middle of the voltage range, but saw the same distored oyutput.

(in the UK, the LT1116 is not available from RS etc)

I am at a loss to understand what is going wrong.

Rich G*ZHA


6cm rf?

militaryoperator
 

5G-6GHz One-Way Microwave RF Power Amplifier Module 40DB SBB5089+SE5004
( 114749899192 )

SE5004 1W Microwave Power Amplifier RF Power Amplifier 5.15GHz-5.85GHz 30DBm
( 114556927546 )

Did anyone try these? Both use the SE5004 which seems rated to 34dbm max, 

I'm guessing the first unit rated at 2W is 2 Chinese Watts. The second unit might just do it.

Probably get 1W out of first but it has more gain so smaller i/p needed I guess.

 Ben.


Hi Speed Comparator operation

G8ZHA
 

I have built a couple of W1GHz projects: a GPS locked 10MHz osillator and a 100MHz PLL board. Each of his circuits uses a LT1116 hi speed comparator to lift the oscilator signal up to 5V CMOS logic levels to feed the dividers.

On the 100MHz PLL PCB, there is a 3.3V osc, feeding a MC12080 Div by 10 prescaler, AC coupled into the non-inverting input ofthe LT1116. The inverting input is tied directly to ground. I can see a nice square wave signal into this pin, about 1.5V pk-pk, centered on 0V. The outputs, which are open circuit, are very distorted, see photos.

I thought that this may be because the signal is outside the common range of 0 - 2.5V for the LT1116, so I biased the input to the middle of the voltage range but was not successful.

Am I missing something obvious?

I also built the 10MHz version, which feeds the osc straight into the comparator. I hadn't got a LT1116, so used a LT1016 instead, which has a common mode input range of 1.25 tp 3.75V range. Again, I biased the input signal to the middle of the voltage range, but saw the same distored oyutput.

(in the UK, the LT1116 is not available from RS etc)

I am at a loss to understand what is going wrong.

Rich G*ZHA


DF9IC 1296 amplifiers

Dennis Sweeney
 

I built eight DF9IC 23 cm amplifiers.  Six worked well and we are enjoying the expanded 1296 activity but one got destroyed with a mistake that resulted in a spectacular arc and the other got overheated in attempting to solder the transistors.  Does anyone have any of the boards left that I can buy so I can rebuild the two remaining amplifiers?

BTW, we started the Blue Ridge Microwave Society (BRMS) in Virginia on our side of the pond.  See groups.io/g/brms.  We have about 95 members and anyone with an interest in amateur microwaves is welcome to join.

73, Dennis WA4LPR


Re: Wavelab 23 GHz connector and PSU PCBs avaialble

Steve G4KNZ
 

I've just assembled my Wavelab 23GHz PSU/Connector boards, just wondering about heatsinking for the 3 large regulators.

The underside of the board has the solder resist cleared, and I thought I'd read somewhere that this was for heatsinking.
But I've no idea what, is this some ordered part, or perhaps some home-made fins that could be soldered to the underside?

Steve G4KNZ


Re: Norton Amplifiers

Neil Smith G4DBN
 

Note dreaming after all. Phew. This is the Appnote I vaguely recalled. Looks like it is about the ZRL-700+ (and the other models)

https://www.minicircuits.com/appdoc/AN60-039.html

Neil G4DBN

On 19/05/2021 19:23, Conrad, PA5Y wrote:
Could you be referring to the HELA10B dual monolithic amplifier? I have a pair of these on my 2-channel adaptive EME system. They are there to overcome splitter losses and give a bit of extra gain for the IQ+. The path for one channel is HELA10B (11db gain 2.5dB NF on 144) then a Band pass filter, then a 3dB hybrid splitter. One side feeds the IQ+ (used for the adaptive RX) and the other my transverter which is used a linear polarisation (either +/- 45 deg) channel with the K3S. The whole system seems to work very well.

I will try one on 432 but the noise figure is significantly higher on the 4 that I built.

https://www.minicircuits.com/app/AN60-009.pdf

You need a heatsink!


Re: Norton Amplifiers

Conrad, PA5Y
 

Could you be referring to the HELA10B dual monolithic amplifier? I have a pair of these on my 2-channel adaptive EME system. They are there to overcome splitter losses and give a bit of extra gain for the IQ+. The path for one channel is HELA10B (11db gain 2.5dB NF on 144) then a Band pass filter, then a 3dB hybrid splitter. One side feeds the IQ+ (used for the adaptive RX) and the other my transverter which is used a linear polarisation (either +/- 45 deg) channel with the K3S. The whole system seems to work very well.

I will try one on 432 but the noise figure is significantly higher on the 4 that I built.

https://www.minicircuits.com/app/AN60-009.pdf

You need a heatsink!

Conrad PA5Y

-----Original Message-----
From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Neil Smith G4DBN via groups.io
Sent: 19 May 2021 20:07
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Norton Amplifiers

I seem to recall seeing the layout of a Minicircuits amp that used hybrids and paired amplifier chains.  One of the benefits siuggested was that if one leg of the amp died, the other would carry one at only 6dB down, as well as being very linear and robust with a high output IP3.  I thought it was the ZRL-700+ but can't find the notes about the internal circuit of that one, so I might be wrong. NF is 2dB at 70cm and the gain is very high, so not much benefit unless it is close to the masthead. It wasn't the TAMP-72LN+ drop-in module either. Perhaps I was dreaming.

Neil G4DBN


Re: Norton Amplifiers

Neil Smith G4DBN
 

I seem to recall seeing the layout of a Minicircuits amp that used hybrids and paired amplifier chains.  One of the benefits siuggested was that if one leg of the amp died, the other would carry one at only 6dB down, as well as being very linear and robust with a high output IP3.  I thought it was the ZRL-700+ but can't find the notes about the internal circuit of that one, so I might be wrong. NF is 2dB at 70cm and the gain is very high, so not much benefit unless it is close to the masthead. It wasn't the TAMP-72LN+ drop-in module either. Perhaps I was dreaming.

Neil G4DBN


Re: Norton Amplifiers

 

On Wed, 19 May 2021 at 18:46, Chris Bartram G4DGU <chris@...> wrote:
My approach, FWIW, to the design of a second stage of a 'bomb-proof'
receiver at 432 or 1296MHz would be to use a group of more modern MMIC
devices such as the PGA-105 combined together with hybrids. Two groups
of two combined using 0degree hybrids and then combined into a push-pull
amplifier would give very good performance, but beware of mixer damage
if you have strong local signals!!

73

Chris G4DGU

I think we need an Eimac 4CX10,000A  as a mixer in contests, with a 4CX250B in the front end. This reminds me, I need to send you some data sheets. I had forgotten about that but will do it asap.

Dave


Norton Amplifiers

Chris Bartram G4DGU
 

Having, courtesy of Dom, seen information on the Norton feedback amplifier circuit, can I just make a couple of comments from rather a lot of direct experience of 'noiseless' feedback linearised amplifiers, and related circuitry, make a few observations and comments?

I'm not suggesting that the basic negative feedback topology doesn't work. It does, but really only in its original format at VHF. The problem is that both the active device and the feedback transformer, like most circuit elements at high frequencies, have phase shifts which can easily combine at frequencies above the operating frequency to produce positive feedback. If the gain of the amplifier is greater than unity at that frequency, a spurious oscillation WILL result! I have a tee-shirt collection ...

Those of us who were using the technique 40 years ago were able to make stable amplifiers using now historical devices like the BFT66, BFR91, BFR96 etc. They worked - with a bit of fiddling, such as a ferrite bead in series with the collector lead simply because the fT of the devices was quite small. I even managed to design a reliable NFB LNA using a C-band GaASFET at VHF, albeit using a different circuit. A lot of these designs found the way into production - indeed the FET amplifier circuit was ripped-off by another designer for an IF preamp design for a military radar!

The Ft of the next generation of bipolar devices was rather greater than that of the previous parts, and the simple Norton approach became untameable. Simply replacing the transistor in DJ7VY's design with something more recent is very likely indeed to result in an 'informal oscillator'!

There are other -ve feedback circuit topologies which can be used to make feedback linearised low-noise amplifiers (and interestingly transmitter power amplifiers) but they suffer from the need to have a hybrid in the input signal path. I have looked at linearising modern broad-band MMICs, but there isn't a simple reproducible topology which I've yet found despite a lot of playing both on the bench and by using modelling. I have achieved good performance from a couple of prototypes at 144, though, with IPI3 figures in the +30dBm region and NFs ~1.2dB, but they haven't proved reproducible.

My approach, FWIW, to the design of a second stage of a 'bomb-proof' receiver at 432 or 1296MHz would be to use a group of more modern MMIC devices such as the PGA-105 combined together with hybrids. Two groups of two combined using 0degree hybrids and then combined into a push-pull amplifier would give very good performance, but beware of mixer damage if you have strong local signals!!

73

Chris

G4DGU


Re: How does this POTY antenna work??

John Fell
 

Chris,
The pic shows a circular patch feed for 2.4GHz , similar to the POTY type .The N elbow feeds 2.4GHz RF to the patch element .
His site says he uses a 20W PA , so depending on the attenuation along the TX cable , he should put in a reasonable signal .

My system outputs 1.5W via a 5m run of LDF450 Heliax via an 80cm offset - that puts my signal at -5dB relative to the Beacons on QO100.

The SMA lead will connect a probe inside the round waveguide to the downconverter behind the assembly. An LNB is a downconverter , in this case a block + antenna .The N elbow plug will carry downconverted RF and DC to the shack end unit that will supply the required output RF for the radio in use.

What is interesting to see is the conical horn and rear choke flange (?) . I would be interested to know what interactions /pattern distortion occur on 2.4GHz .
Certainly the feed will be more efficient than open ended waveguide at 10GHz .

73
John
G0API

On Wed, 19 May 2021 at 10:32, Chris Wilson <chris@...> wrote:


  19/05/2021 10:19

I am slowly getting into amateur satellite work and runa 1.8 meter prime focus dish with a POTY antenna for 2.4GHz TX and a coaxial LNB for circa 10.5GHz reception. I know the LNB down converts to around 940 MHz using an intermediate frequency.

I heard a very nice signal from a chap who appeared to know a lot about the hardware used, so looked him up on qrz.com  He was using a POTY antenna the like of which I have not seen before. It has a feed horn and appears to feed the RX side without an LNB directly to a Kuhne down converter. How might that work, I thought down converters expected a lot of gain from the LNB and an already down converted signal, to some extent, done within the LNB?


I placed a photo of this nicely looking engineered device here:

http://www.chriswilson.tv/DJ8EI.JPG

It appears there's no LNB but the RX antenna is inside the POTY tube itself.


Thanks for any insight to this newbie!

--
       Best Regards,
                   Chris Wilson.
mailto: chris@...







Re: 6cm lo?

Gareth G4XAT
 

I have down-converted 5.66 DATV to 3.4 and fed it into a Titanium LNB  via a 1/4 wave probe (C1WPLL 3.4-4.2GHz) which mixes again down to 950-1750.
With some pipe caps to clean up the LO (2260 from a DDS) and the desired mixer output (3.4). Very pleased with how its working on the bench. BATC Ryde for DATV and Langstone for NB. 
Gareth


Re: 6cm lo?

militaryoperator
 

-----Original Message-----
From: geoffrey pike via groups.io <gi0gdp@...>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Sent: Tue, 18 May 2021 17:40
Subject: Re: [UKMicrowaves] 6cm lo?

Try here


Thanks Geoff, 

5760 Lo on its way. Have also bought some W1GHZ boards for some 23cm preamps along with PGA103 devices.

Fun fun fun ahead!!!!!!

Ben.


Re: Farnell Handling Charge

Michael Scott
 

Sorry Mark, we have a few MAX ICs but not that one!

The whole catalogue is on the UKuG website, folow the links to the Chipbank.

73, Mike

On 19/05/2021 03:59, Mark M5BOP via groups.io wrote:
You don’t happen to have a supply of MAX4450EXK+T 210MHz op amps, SC-70-5 in the chipbank do you Mike?  If so, I’ll take ten! That would save me an order to Farnell or similar (with associated low-volume order costs!) - not building a 10MHz ref DA or anything!!

Thanks,
Mark M5BOP

Farnell Handling Charge 
From: Michael Scott
Date: Mon, 17 May 2021 16:31:27 BST 

Have to use the Chipbank instead!!

Mike.


3c. 
Re: Farnell Handling Charge 
From: Andy G4JNT
Date: Mon, 17 May 2021 16:35:02 BST 
I only wanted a handful of TS912 opamps.


Re: How does this POTY antenna work??

Colin G4EML
 

The Kuhne down converter does exactly the same job as a regular LNB. It just has a coax input instead of having an integral antenna. That arrangement simply connects an external antenna to it.

It is not really correct to call that a POTY antenna. The POTY is the name of a specific design, not a generic term.

Colin G4EML

On 19 May 2021, at 10:32, Chris Wilson <chris@chriswilson.tv> wrote:



19/05/2021 10:19

I am slowly getting into amateur satellite work and runa 1.8 meter prime focus dish with a POTY antenna for 2.4GHz TX and a coaxial LNB for circa 10.5GHz reception. I know the LNB down converts to around 940 MHz using an intermediate frequency.

I heard a very nice signal from a chap who appeared to know a lot about the hardware used, so looked him up on qrz.com He was using a POTY antenna the like of which I have not seen before. It has a feed horn and appears to feed the RX side without an LNB directly to a Kuhne down converter. How might that work, I thought down converters expected a lot of gain from the LNB and an already down converted signal, to some extent, done within the LNB?


I placed a photo of this nicely looking engineered device here:

http://www.chriswilson.tv/DJ8EI.JPG

It appears there's no LNB but the RX antenna is inside the POTY tube itself.


Thanks for any insight to this newbie!

--
Best Regards,
Chris Wilson.
mailto: chris@chriswilson.tv

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