Date   

Re: Adalm Pluto Revision D

Simon Brown
 

Very nice.

 

I have a modified Pluto (Thanks to DD1US who did the mod) and feed it with 40MHz from a dual Leo Bodnar unit.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Mark G6DDX
Sent: 20 May 2021 21:59
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Adalm Pluto Revision D

 

I received an Adalm Pluto today from Digikey which is revision D.  This revision has clock in and out connectors and also RX2/TX2 wired out.  All four ports are provided through u.fl sockets on the pcb.

Details from from Analog Devices below

Image - https://wiki.analog.com/_media/university/tools/pluto/hacking/pluto_c.png
Mine has 3.3V max silked screened next to the clock input.

Wiki - https://wiki.analog.com/university/tools/pluto/hacking/hardware#revision_d

73 de Mark, G6DDX


Re: 6cm rf?

Mark GM4ISM
 

Ben

160 C junction temperature  is pretty standard for this technology, the data that is missing is the thermal resistance, junction to case measured in C/W, and power added efficiency.  Without it you cannot calculate the permitted dissipation of the device and the expected output power WRT the junction temperature. Yes it can manage a P1dB of 2W  but maybe only with a 20% duty cycle for thermal considerations.

If the value  of thermal resistance is say 15C/W, then if you dissipate 5W in the junction, the junction rises to 75 degrees above the case,  that would be manageable as the heatsink would have to keep the case at a max of 85C

if the value is 30 then the same 5W dissipation would put the junction at 170C even if you kept the case anchored at 20C with a fantastic heat sink.

we can guess from the figures.. at 400mW the data sheets states that the max case temperature is 85C  and that this is at 5V and 600mA  That is 3W in, 400mW out   2.6W dissipation  ie about 14% efficiency

If you assume that  at these values the case temperature is allowed to approach the max of 85C the the junction will also be OK below 160 C, some 75C above case.  75/2.6 is  28.8 C/W thermal resistance.

Lets say the efficiency reaches 30% at the P1dB point of 2w out,  that would require a junction dissipation of 4.4W

With that thermal resistance which is a constant, the junction would be 127C above the case. Thus the case must not rise above 33C

Thats quite low, requiring a very good heatsink and likely a low duty cycle

These calculations make a few assumptions and may be quite a bit off, I may even have  made a slip on the calculator  but they look about right to me and support the supposition that  1W or maybe a bit more output, with good design and typical amateur duty cycles, is probably feasible.

There are a lot of devices out there that look good for really high output power at the P1dB point but being designed (thermally) for a lower mean power  means they just cant realise that P1dB for a useful time.  Not all data sheets tell you the whole story :(

Mark GM4ISM

On 20/05/2021 21:26, militaryoperator via groups.io wrote:
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.

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,

Virus-free. www.avg.com


Re: Dish Mesh information

Mike GD6ICR
 

Thanks to John API  and ZTR for your advice - It seems I do have a sectional dish available to me which I hope despite the age will give one or two of us on the Island access to EME on the likes of 23/13/3cm in the future. I realize the problems with the weight of the dish if stainless mesh is used, but you must realize that aluminium mesh/perforated metal here on the Island where no-where is more than 7 miles from the sea, that the corrosive capability of salt air here is phenominal. I still need to find the right paint to coat all the dishes we have available - any advice on the right material coating whether its brushed or sprayed I do have the capability and If i dont there are a lot of skill within the community to help. Just hope they dont mind a 12 ft dish on my garage roof or moved onto the back of my trailer to tow to the best places for competitions and eme. Thanks for all your suggestions both on here and direct
We all need to find our way.
--
Mike GD6ICR IO74PF73TW


Re: 6cm rf?

geoffrey pike
 

Hi Ben,
Have you looked at the FPV booster amps for drones?, i used these on 5.8 GHz Analogue ATV from memory they use
a pair of devices and achieve 4 Chinese watts
cheers
Geoff
GI0GDP

On Thursday, 20 May 2021, 11:44:33 BST, militaryoperator via groups.io <military1944@...> 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.


Adalm Pluto Revision D

Mark G6DDX
 

I received an Adalm Pluto today from Digikey which is revision D.  This revision has clock in and out connectors and also RX2/TX2 wired out.  All four ports are provided through u.fl sockets on the pcb.

Details from from Analog Devices below

Image - https://wiki.analog.com/_media/university/tools/pluto/hacking/pluto_c.png
Mine has 3.3V max silked screened next to the clock input.

Wiki - https://wiki.analog.com/university/tools/pluto/hacking/hardware#revision_d

73 de Mark, G6DDX


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

2481 - 2500 of 64936