Topics

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


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


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@...


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


Pete - GM4BYF
 

Just seen your message. I have a circuit diagram somewhere, having repaired mine several times. One thing to notice is that the coaxial relays have insufficient isolation on their own, so the input circuit has an additional isolation relay to earth it when on transmit. I also found that a delay of 0.3s was necessary to protect the output of the preamp and allow time for the relays to change over. Get back to me for more detailed information if required.

73
Pete GM4BYF
On 10/01/21 18:49, Anthony Coldman via 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


--
vry 73
Pete GM4BYF


DF6NA Rainer
 


73, Rainer DF6NA

Am 11.01.2021 um 20:17 schrieb Pete - GM4BYF via groups.io:

Just seen your message. I have a circuit diagram somewhere, having repaired mine several times. One thing to notice is that the coaxial relays have insufficient isolation on their own, so the input circuit has an additional isolation relay to earth it when on transmit. I also found that a delay of 0.3s was necessary to protect the output of the preamp and allow time for the relays to change over. Get back to me for more detailed information if required.

73
Pete GM4BYF
On 10/01/21 18:49, Anthony Coldman via 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


--
vry 73
Pete GM4BYF


Anthony Coldman
 

Many thanks to all that responded, I now have the circuit for the MK2 that I needed.

 

Regards Anthony

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Pete - GM4BYF via groups.io
Sent: 11 January 2021 19:17
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] SSB - Electronic SP-23 Preamp

 

Just seen your message. I have a circuit diagram somewhere, having repaired mine several times. One thing to notice is that the coaxial relays have insufficient isolation on their own, so the input circuit has an additional isolation relay to earth it when on transmit. I also found that a delay of 0.3s was necessary to protect the output of the preamp and allow time for the relays to change over. Get back to me for more detailed information if required.

73
Pete GM4BYF

On 10/01/21 18:49, Anthony Coldman via 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


--
vry 73
Pete GM4BYF