High IP 2nd stage for 432MHz


Conrad, PA5Y
 

Hello all.

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

The PGA105+ 



almost fits the bill but maybe there is something better?

Ideas anyone?


Colin Ranson
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 


Conrad, PA5Y
 

Hello Colin, far too much gain. 

Regards

Conrad


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs@...>
Sent: 17 May 2021 12:05
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 


ian hope (2E0IJH)
 

what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH

 
 
Sent: Monday, May 17, 2021 at 11:40 AM
From: "Conrad, PA5Y" <g0ruz@...>
To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs@...>
Sent: 17 May 2021 12:05
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 


ian hope (2E0IJH)
 

Forgot to add this, http://www.farnell.com/datasheets/1227369.pdf
 
Ian
M5IJH

 
 
Sent: Monday, May 17, 2021 at 12:40 PM
From: "ian hope (2E0IJH)" <ian@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH
 
 
Sent: Monday, May 17, 2021 at 11:40 AM
From: "Conrad, PA5Y" <g0ruz@...>
To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs@...>
Sent: 17 May 2021 12:05
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 


Andy G4JNT
 

Throttle the gain back with a attenuator if you need to.
Gain comes cheap these days



On Mon, 17 May 2021 at 12:40, ian hope (2E0IJH) <ian@...> wrote:
what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH
 
 
Sent: Monday, May 17, 2021 at 11:40 AM
From: "Conrad, PA5Y" <g0ruz@...>
To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs=hotmail.com@groups.io>
Sent: 17 May 2021 12:05
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 


Conrad, PA5Y
 

Hi Andy, yes but I am considering the IP3 as well. I would rather only attenuate by 3dB at most, these devices with 19dB in gain front of them will start to suffer. I have not seen any big signals OOB signals and I will put a BPF before it so maybe I am worrying unduly. I would rather have some margin here.

Regards

Conrad PA5Y


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Andy G4JNT via groups.io <andy.g4jnt@...>
Sent: 17 May 2021 13:46
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 
Throttle the gain back with a attenuator if you need to.
Gain comes cheap these days



On Mon, 17 May 2021 at 12:40, ian hope (2E0IJH) <ian@...> wrote:
what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH
 
 
Sent: Monday, May 17, 2021 at 11:40 AM
From: "Conrad, PA5Y" <g0ruz@...>
To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs=hotmail.com@groups.io>
Sent: 17 May 2021 12:05
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
Sent: 17 May 2021 09:55
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 


Dominique Dehays
 

 

Hi Conrad and all ,

 

if , like me , U sometimes prefer to use old fashion things ( like garters for girls for exemple) , U could use:

http://www.marsport.org.uk/dubus/archive/9202-3.pdf

it is a DJ7VY design revamped by DJ9BV

73

Dom

 

 

 

> Message du 17/05/21 14:09
> De : "Conrad, PA5Y" <g0ruz@...>
> A : "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
> Copie à :
> Objet : Re: [UKMicrowaves] High IP 2nd stage for 432MHz
>
>
Hi Andy, yes but I am considering the IP3 as well. I would rather only attenuate by 3dB at most, these devices with 19dB in gain front of them will start to suffer. I have not seen any big signals OOB signals and I will put a BPF before it so maybe I am worrying unduly. I would rather have some margin here.

>
Regards

>
Conrad PA5Y
 

>

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Andy G4JNT via groups.io <andy.g4jnt@...>
> Sent: 17 May 2021 13:46
> To: UK Microwaves groups.io <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 
Throttle the gain back with a attenuator if you need to.
Gain comes cheap these days

>
Andy

>

>

>
On Mon, 17 May 2021 at 12:40, ian hope (2E0IJH) <ian@...> wrote:
>
what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH
 
 
Sent: Monday, May 17, 2021 at 11:40 AM
> From: "Conrad, PA5Y" <g0ruz@...>
> To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs=hotmail.com@groups.io>
> Sent: 17 May 2021 12:05
> To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
> Sent: 17 May 2021 09:55
> To: UKMicrowaves@groups.io
> Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 

>

>


Andy G4JNT
 

The spec for the PGA103, at 400MHz  shows  Output IP3 as +39dBm and gain 22dB,  noise figure 0.5dB
That equates to input IP3 of +17dBm

That old design with transformer feedback around a bipolar quotes +17dBm I/P IP3 (the same ass PGA-103) a lower gain of 10dB and noise figure 1.1dB

IRMC.   Things have moved on





On Mon, 17 May 2021 at 14:33, Dominique Dehays <f6dro@...> wrote:

 

Hi Conrad and all ,

 

if , like me , U sometimes prefer to use old fashion things ( like garters for girls for exemple) , U could use:

http://www.marsport.org.uk/dubus/archive/9202-3.pdf

it is a DJ7VY design revamped by DJ9BV

73

Dom

 

 

 

> Message du 17/05/21 14:09
> De : "Conrad, PA5Y" <g0ruz@...>
> A : "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
> Copie à :
> Objet : Re: [UKMicrowaves] High IP 2nd stage for 432MHz
>
>
Hi Andy, yes but I am considering the IP3 as well. I would rather only attenuate by 3dB at most, these devices with 19dB in gain front of them will start to suffer. I have not seen any big signals OOB signals and I will put a BPF before it so maybe I am worrying unduly. I would rather have some margin here.

>
Regards

>
Conrad PA5Y
 

>

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Andy G4JNT via groups.io <andy.g4jnt=gmail.com@groups.io>
> Sent: 17 May 2021 13:46
> To: UK Microwaves groups.io <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 
Throttle the gain back with a attenuator if you need to.
Gain comes cheap these days

>
Andy

>

>

>
On Mon, 17 May 2021 at 12:40, ian hope (2E0IJH) <ian@...> wrote:
>
what about a ATF531, used in a lot of EME preamps, but again the gain may be too high for you
 
ian
M5IJH
 
 
Sent: Monday, May 17, 2021 at 11:40 AM
> From: "Conrad, PA5Y" <g0ruz@...>
> To: "UKMicrowaves@groups.io" <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
Hello Colin, far too much gain. 
 
Regards
 
Conrad
 
 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Colin Ranson via groups.io <g8lbs=hotmail.com@groups.io>
> Sent: 17 May 2021 12:05
> To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
> Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 

Conrad,

 

What about the good old PGA-103 +  ?

 

Regards

 

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Conrad, PA5Y
> Sent: 17 May 2021 09:55
> To: UKMicrowaves@groups.io
> Subject: [UKMicrowaves] High IP 2nd stage for 432MHz

 

Hello all.

 

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

 

The PGA105+ 

 

 

 

almost fits the bill but maybe there is something better?

 

Ideas anyone?

 

 

>

>


John Quarmby
 

Another device to consider is the AH1, noise figure not quite as good but better OIP3 and around the same gain at 500MHz. Needs a good board to achieve adequate heatsinking as the device dissipates 750mW (5V at 150mA).


73


John G3XDY

On 17/05/2021 08:54, Conrad, PA5Y wrote:
Hello all.

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

The PGA105+ 



almost fits the bill but maybe there is something better?

Ideas anyone?

Virus-free. www.avast.com


Andy G4JNT
 

MiniCircuits PHA-1 is quoted as a replacement for that.

Nice device



On Mon, 17 May 2021 at 15:40, John Quarmby via groups.io <g3xdy=btinternet.com@groups.io> wrote:

Another device to consider is the AH1, noise figure not quite as good but better OIP3 and around the same gain at 500MHz. Needs a good board to achieve adequate heatsinking as the device dissipates 750mW (5V at 150mA).


73


John G3XDY

On 17/05/2021 08:54, Conrad, PA5Y wrote:
Hello all.

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

The PGA105+ 



almost fits the bill but maybe there is something better?

Ideas anyone?

Virus-free. www.avast.com


Conrad, PA5Y
 

That is a good choice Andy. 

I have some as well. They are used in my IQ+ diversity RX so last time I made mini circuits order I bought some. As John says, that amount of heat dissipation needs some consideration.

Regards 

Conrad


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Andy G4JNT via groups.io <andy.g4jnt@...>
Sent: 17 May 2021 16:57
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] High IP 2nd stage for 432MHz
 
MiniCircuits PHA-1 is quoted as a replacement for that.

Nice device



On Mon, 17 May 2021 at 15:40, John Quarmby via groups.io <g3xdy=btinternet.com@groups.io> wrote:

Another device to consider is the AH1, noise figure not quite as good but better OIP3 and around the same gain at 500MHz. Needs a good board to achieve adequate heatsinking as the device dissipates 750mW (5V at 150mA).


73


John G3XDY

On 17/05/2021 08:54, Conrad, PA5Y wrote:
Hello all.

I have been plugging the numbers into the VK3UM EME calculator clearly shows that with 19dB gain in my LNA, 4.5dB of RX cable loss and 1 dB loss in my bandpass filter followed by 2dB NF of my transverter I need a 2nd stage amplifier for EME. I can improve my system noise figure by 1dB with a 10dB gain amplifier. I am reluctant to put the 2nd stage at the masthead because for contests I will not have it in circuit. Spec should be a Noise figure of 1.5dB max, 10-12dB gain and a very high IIP3. 

The PGA105+ 



almost fits the bill but maybe there is something better?

Ideas anyone?

Virus-free. www.avast.com


Greg - ZL3IX
 

The gain of many low noise bipolar devices can be reduced with a small inductor in the emitter. Unlike resistive feedback It doesn't degrade the noise figure, and the stability doesn't suffer either. The input impedance is also raised up to a usable value. I've made many low noise amps for UHF using this technique.

73, Greg, ZL3IX