A look at my Symmetricom GPSDO / 10MHz reference (OCXO + Furuno receiver)

[thinkfat]

Those black "puck" antennas usually work fine, even with the rather "deaf" Furuno receivers (I have one with a Symmetricom OCXO). However, I had one that went bust after a couple of weeks operation, so those things happen. Not all is lost, but if the receiver isn't able to track a decent amount of sats with one of those cheap pucks, things are not looking good.

[Tom45]

if the receiver isn't able to track a decent amount of sats with one of those cheap pucks, things are not looking good.

I had an apparently dead puck antenna once and just set it aside. Eventually it resurfaced and before throwing it away I looked at it closely. The center pin of the SMA connector was missing! Cut that off and installed a new SMA connector and it now works great.

As far as I know, the connector with missing center pin was installed that way at the factory.

[LukGasp]

After installing the antenna outside with a clear view to the sky, I tried connecting the Symmetricon to the Lady Heather software on my notebook running Win10. Used COM port 6 and 57600, but no signs of life, though it works along with putty.
Any ideas of what I may have mistaken?

Comments appreciated.

Thank you!

[ordnit]

Hi there,
thank you for valuable information I get everyday from the list.

After a very long time I managed to power up a Trimble GPSDO, connected
to an aexternal antenna.

UCCM >*IDN?
TRIMBLE,57964-15,86854165,V3.0.0.11-01
Datecode: 0814 (pretty old, but still in its teen years)

Some output from "common commands":

UCCM >SYSTem:STATus?

-------------------------------------------------------------------------------
57964-15     serial number  86854165     firmware ver  3.0.0.11-01LINK  mode
-------------------------------------------------------------------------------
Reference Status __________________________   Reference Outputs _______________
XX Ref 8KHz 0: [LOS]
XX Ref 8KHz 1: [LOS]                          TFOM     4            FFOM      1
XX Ref 8KHz 2: [LOS]                          UCCM A Status[OCXO WARMUP]
XX Ref 8KHz 3: [LOS]
>> GPS: [phase:-3.3E-05, settling]
ACQUISITION ...................................................[GPS 1PPS Valid]
Tracking: 8 ____   Not Tracking: 3 ________   Time ____________________________
PRN  El  Az  C/N   PRN  El  Az                GPS      11:44:34     27 Jul 2021
 32  39 107   46     3  10 226
  1  28 284   37    16   6 189                ANT DLY  0 ns
 10  40  51   42    14   8 327                Position ________________________
  8  79 239   45                              MODE     Hold
 23   7  49   38
 21  52 297   43                              LAT      N  43:35:11.819
 27  55 153   43                              LON      E  13:31:1.250
 22  32 230   41                              HGT              +225.27 m (MSL)


ELEV MASK  5 deg
-------------------------------------------------------------------------------

UCCM >POSSTATus

---------------------------------------------
 07/27/2021  11:44:57
---------------------------------------------
 Position: LAT(N  43:35:11.819) LON(E  13:31:1.250) H(        +225.27 m MSL)
---------------------------------------------
 Geometry: PDOP(0.0) HDOP(0.0) VDOP(0.0)
 num of visible sats >  10
 num of sats tracked >  10
  -------- Receiver Channel State --------
 CH  0 > SateID(03) TrackMode(pos avail) SigValue(36)
 CH  1 > SateID(32) TrackMode(pos avail) SigValue(47)
 CH  2 > SateID(01) TrackMode(pos avail) SigValue(37)
 CH  3 > SateID(16) TrackMode(pos avail) SigValue(34)
 CH  4 > SateID(10) TrackMode(pos avail) SigValue(42)
 CH  5 > SateID(08) TrackMode(pos avail) SigValue(44)
 CH  6 > SateID(14) TrackMode(tracking ) SigValue(20)
 CH  7 > SateID(23) TrackMode(pos avail) SigValue(37)
 CH  8 > SateID(21) TrackMode(pos avail) SigValue(44)
 CH  9 > SateID(27) TrackMode(pos avail) SigValue(43)
 CH  10 > SateID(22) TrackMode(pos avail) SigValue(40)
 CH  11 > SateID(00) TrackMode(tracking ) SigValue( 0)
---------------------------------------------
 Rcvr Status(1):
---------------------------------------------
 Antenna Voltage:  5000.00mV   , Antenna Current:     0.00mA

UCCM >status

               - UCCM Slot STATE-

1-1. #Now ACTIVE STATUS ---------------- [OCXO Warm]
1-2. #Before ACTIVE STATUS ------------- [Alarm]
2-1. #Reference Clock Operation -------- [Not Used]
2-2. #Current Reference Type ----------- [GPS]
2-3. #Current Select Reference --------- [GPS 1PPS]
2-4. #Current Reference Status --------- [Good Accuracy & Stable]
     #GPS STATUS ----------------------- [Available]
     #Priority Level ------------------- [LINK > GPS]
     #ALARM STATUS
     #H/W FAIL [ LINK ]
     #OPERATION ALARM ------------------ [Antenna]
3-1. #PLL STATUS ----------------------- [DISABLE]
3-2. #Current PLL MODE ----------------- [OFFSET OBSERVATION MODE]


The issue I'm facing is following: even after a long uptime, I never com to a "fast blinking led" and PLL status "enabled". Monitoring device with LHv6, shows an "operation mode" alternating Locked (few seconds" and "recvery". TFOM is quite always 3 or 4. Power supply is linear, with output voltage 5.6V or 6V. I made many tests but had no luck.

Sys:stat showa a "phase" value moving from -1.4E-05,settling up to
-4.3E-06, settling. On an old post I read that it might be caused by the oscillator drifting due to age.

Any guess? Do I have to throw the unit from the window? For your reference, I have a samsung unit connected to same antenna via a splitter. The GPSDO is performing very well.
I think user WKB had a similiar issue.

Thank you in advance for help.
Best regards.

[ordnit]

Hi there,
Update on my issue:

Yesterday I made some testing, removing the splitter and nothing changed (apart the samsung complaining about signal loss   ).

I removed the trimble board from its case, I gave a look to it and powered up again: well... may be a kind of magic but it works. Now the status led is blinking fast and this is the output I get from commands:

UCCM >STATus

               - UCCM Slot STATE-

1-1. #Now ACTIVE STATUS ---------------- [Master Manual]
1-2. #Before ACTIVE STATUS ------------- [OCXO Warm]
2-1. #Reference Clock Operation -------- [Not Used]
2-2. #Current Reference Type ----------- [GPS]
2-3. #Current Select Reference --------- [GPS 1PPS]
2-4. #Current Reference Status --------- [Good Accuracy & Stable]
     #GPS STATUS ----------------------- [Available]
     #Priority Level ------------------- [LINK > GPS]
     #ALARM STATUS
     #H/W FAIL [ LINK ]
     #OPERATION ALARM ------------------ [Antenna]
3-1. #PLL STATUS ----------------------- [ENABLE]
3-2. #Current PLL MODE ----------------- [OFFSET OBSERVATION MODE]

UCCM >SYSTem:STATus?

-------------------------------------------------------------------------------
57964-15     serial number  86854165     firmware ver  3.0.0.11-01LINK   mode
-------------------------------------------------------------------------------
Reference Status __________________________   Reference Outputs _______________
XX Ref 8KHz 0: [LOS]
XX Ref 8KHz 1: [LOS]                          TFOM     3            FFOM      1
XX Ref 8KHz 2: [LOS]                          UCCM A Status[ACTIVE]
XX Ref 8KHz 3: [LOS]
>> GPS: [phase:-4.8E-06, settling]
ACQUISITION ...................................................[GPS 1PPS Valid]
Tracking: 10 ___   Not Tracking: 0 ________   Time ____________________________
PRN  El  Az  C/N   PRN  El  Az                GPS      07:35:47     29 Jul 2021
 26  73 268   45
 31  22 215   37                              ANT DLY  0 ns
 16  45 309   42                              Position ________________________
 10  11 170   38                              MODE     Hold
 29  32  77   43
 25   6 141   34                              LAT      N  43:35:11.808
 18  79  73   45                              LON      E  13:31:1.216
  5  18  45   39                              HGT              +228.84 m (MSL)
 23  31 143   42
 27  19 281   40

UCCM >posstatus

---------------------------------------------
 07/29/2021  07:36:06
---------------------------------------------
 Position: LAT(N  43:35:11.808) LON(E  13:31:1.216) H( +228.84 m MSL)
---------------------------------------------
 Geometry: PDOP(0.0) HDOP(0.0) VDOP(0.0)
 num of visible sats >  10
 num of sats tracked >  10
  -------- Receiver Channel State --------
 CH  0 > SateID(26) TrackMode(pos avail) SigValue(46)
 CH  1 > SateID(31) TrackMode(pos avail) SigValue(36)
 CH  2 > SateID(16) TrackMode(pos avail) SigValue(42)
 CH  3 > SateID(10) TrackMode(pos avail) SigValue(37)
 CH  4 > SateID(29) TrackMode(pos avail) SigValue(42)
 CH  5 > SateID(25) TrackMode(pos avail) SigValue(36)
 CH  6 > SateID(18) TrackMode(pos avail) SigValue(45)
 CH  7 > SateID(05) TrackMode(pos avail) SigValue(40)
 CH  8 > SateID(23) TrackMode(pos avail) SigValue(43)
 CH  9 > SateID(27) TrackMode(pos avail) SigValue(38)
 CH  10 > SateID(00) TrackMode(tracking ) SigValue( 0)
 CH  11 > SateID(00) TrackMode(tracking ) SigValue( 0)
---------------------------------------------
 Rcvr Status(1):
---------------------------------------------
 Antenna Voltage:  5000.00mV   , Antenna Current:     0.00mA


UCCM >DIAGnostic:LOG:READ:ALL?

Log status:  22 entries

L00:21/07/28.06:00:47 Self survey started
L01:21/07/28.06:05:30 Ref Change: GPS
L02:21/07/28.06:09:10 Ref Change: No reference
L03:21/07/28.06:09:25 Ref Change: GPS
L04:21/07/28.06:09:54 Ref Change: No reference
L05:21/07/28.06:10:07 Ref Change: GPS
L06:21/07/28.06:32:45 Ref Change: No reference
L07:21/07/28.06:33:07 Ref Change: GPS
L08:21/07/28.06:34:42 Self survey completed
L09:21/07/28.06:36:13 Ref Change: No reference
L10:21/07/28.06:36:25 Ref Change: GPS
L11:21/07/28.06:58:13 Ref Change: No reference
L12:21/07/28.06:58:25 Ref Change: GPS
L13:21/07/28.07:07:27 Ref Change: No reference
L14:21/07/28.07:07:43 Ref Change: GPS
L15:21/07/28.07:31:43 Ref Change: No reference
L16:21/07/28.07:31:55 Ref Change: GPS
L17:21/07/28.08:35:59 GPS Antenna open
L18:21/07/28.08:36:01 Ref Change: No reference
L19:21/07/28.08:36:30 Ref Change: GPS
L20:21/07/28.12:13:02 Output mode: Active
L21:21/07/28.12:13:02 A/S change: Slave(HIGH)


So far, so good.

PS: I don't belive in magic, so I guess that some glue I used to hold the board, added some capacitive side effects. Let's keep it going, wating for a new GPSDO to join the collection.

[ZigmundRat]

Good to see it working for you.  A couple of things:

-) Certainly it seems that the case interfered with it somehow.  Did you put it in the case or is it one that came from that way?
-) The log entries are interesting. At what point did remove the unit from the case? That flipping of the reference seems peculiar. Is pin 39 of the 50 pin connector grounded?
-) The original problem could have been an OCXO drift issue. It might be that it took this long to settle down. It might be of interest to track the EFC/DAC to see if there’s still significant drift (albeit within the loop tracking ability).
-) From the first log entry to the last where it finally goes active is over six hours - that’s a long time. If you restart the unit, does it lock up faster now?

(Sorry about the delayed reply)

[maskedviperus]

I ordered 3 of these symm uccm units. Still waiting for one of them.  One came with u9 missing but good tracks, the other came with u17 mostly ripped off with the tracks still attached to the legs  ....but it had a good u9  .......quickly had a board running with an oscilloquartz 12v ocxo and all the necessary bits scattered around it.  Got a box for it and got everything mostly finished today/last night and really started messing with it today - as in - let it run for a lil longer than just seeing a command line.

I can confirm everyone else - its picky on power.  Got a baby sized meanwell 5v unit to run it...waiting for mail to come with an aluminum enclosure to make my own psu lol....

as far as i can tell its working fine

Edit:
If anyone is interested in reversing the flash (tsop48 spansion - looks like the right adapter with the right version of a tl866 would read it) ....I would be willing to remove it from a bad board and mail it to anyone who can dump it and post it.... I dont have a tl866 (however this is an argument for one )

Double edit.

I ordered something ill post a dump this weekend.

[ordnit]

Hi @ZigmundRat,
delayed answer to your questions:


-) Certainly it seems that the case interfered with it somehow.  Did you put it in the case or is it one that came from that way?
- The unit came (many years ago) without case and cable. So I arranged a new home for the board. The board lays on a sheet of wool, which acts as a mechanical filter. I don't think it's interfering with the electronics.

-) The log entries are interesting. At what point did remove the unit from the case? That flipping of the reference seems peculiar. Is pin 39 of the 50 pin connector grounded?
- As I started the survey, the unit had been removed from the case and put back in, without the glue. Being the unit "cableless" I can not wire 39 to ground. I should have a cable somewhere in the lab, I'll try this. (see below)

-) The original problem could have been an OCXO drift issue. It might be that it took this long to settle down. It might be of interest to track the EFC/DAC to see if there’s still significant drift (albeit within the loop tracking ability).
I think so. Maybe the oscillator has gone nuts. It's a pretty old unit, and nobody knows its history. Maybe a defective one. Unfortunately at the time i bought it, I had no clear sky view, and was unable to test it. So I had to wait 5+ years to connect to an antenna. As soon as I have some spare time I'll try to log voltage with Labview, provided that the USB interface starts to work.

-) From the first log entry to the last where it finally goes active is over six hours - that’s a long time. If you restart the unit, does it lock up faster now?
I just restarted the unit. Let's see that happens.

After more than one day, the Trimble UCCM has not been able to recover. So the led is not "blinking fast" and I need to shut it down for holidays. This morning I was able to tie pin 39 to ground, but nothing changed. As soon as I return to the office, I'll make more tests or I'll buy a new Samsung or maybe a Thunderbolt.

Thank you for your help! Best regards.

[maskedviperus]

I promised a dump of the spansion chip over a week ago.

I have not looked through it yet.  Bin is zipped

[ve7xen]

I promised a dump of the spansion chip over a week ago.

I have not looked through it yet.  Bin is zipped

Amazing! Thanks! Which processor is used on your version of the card? I only have the Trimble and Samsung variants. If you could also share the full boot log that might help (particularly image sizes / checksums).

Edit: I found that the processor is a Renesas/Hitachi DF2317VTE25V (H8S/2000 ISA). Not great for reversing, since it is not supported in Ghidra.

Edit2: The extracted image seems to be byte-swapped, not sure if this is an artifact of the extraction method, or if it is perhaps some quirk of the board. After byte-swapping, there seems to be some evidence of previously unknown commands, but without the hardware in hand to guess-and-test, and without a working disassembler I can't do much to figure out how to use them.

[maskedviperus]

Hey Ve7xen,

Its the symmetricom uccm. Renaesis.  0949 rev c. Same one this entire thread is based upon.

It would be impossible to obtain a boot log from this board, as it was one of the ones I received damaged. (u17 along with the traces ripped off).  Im not about to tear apart my good one to get to the chip - went thru hell making the thing work in the first place.

Sometime this week? Next week? Tomorrow even? I have another one coming - not sure - aliexpress keeps doin their thing "combining" my orders and it keeps taking longer.  Ill dump and upload it when it arrives.

I tried running it in ghidra but I really dont know what I'm doing../..edit: nvm not supported...

ida?

Ill try another dump in the morning by soldering it to a carrier board (rather than zif), but Im leaning towards it being a clean dump.

 EDIT:

In the zip are two new bin files.  First one was soldered to a carrier board.  Second one was in the zif socket.  After going from the solder method back to zif, I had a lot of issues getting pins to line up and work right - wasnt til after I gave the chip a good soak in iso did it start reading again.

Also did a readout as the cypress equivalent part number for good measure. 

[ve7xen]

Hey Ve7xen,

Its the symmetricom uccm. Renaesis.  0949 rev c. Same one this entire thread is based upon.

It would be impossible to obtain a boot log from this board, as it was one of the ones I received damaged. (u17 along with the traces ripped off).  Im not about to tear apart my good one to get to the chip - went thru hell making the thing work in the first place.

Sometime this week? Next week? Tomorrow even? I have another one coming - not sure - aliexpress keeps doin their thing "combining" my orders and it keeps taking longer.  Ill dump and upload it when it arrives.

I tried running it in ghidra but I really dont know what I'm doing../..edit: nvm not supported...

ida?

Ill try another dump in the morning by soldering it to a carrier board (rather than zif), but Im leaning towards it being a clean dump.

 EDIT:

In the zip are two new bin files.  First one was soldered to a carrier board.  Second one was in the zif socket.  After going from the solder method back to zif, I had a lot of issues getting pins to line up and work right - wasnt til after I gave the chip a good soak in iso did it start reading again.

Also did a readout as the cypress equivalent part number for good measure.

The dump looks clean, wasn't suggesting there was something wrong with it. I guess that the flash is used in 16-bit mode and has just been wired to the processor opposite to how the reader was wired/configured. No big deal, easy to address in software. Once byte-swapped I've been able to identify some image headers and such things, but the bytecode is impenetrable without a disassembler (and really one integrated into Ghidra, since I'm not willing to use an external one manually for this). I might try a pirated copy of IDA Pro and see if there's anything obvious.

Thanks for the better photo of the back of the board, I knew you were referring to that version of the module, but I couldn't find a good enough photo of the chip identifiers to identify it (though with the existing poor images, some guessing, and some Google-Fu I was able to glean enough to identify it anyway).

[ordnit]

Hi all,
I'm back from the holidays (actually since two weeks) and I managed to make some more tests on my Trimble GPSDO to try to tame it.

First test:
Oscillator was removed from the board, I powered it up with a clean 6V linear PSU and logged the current, just to see if the thermal regulation is good or not. The current goes up and then settles down to 450mA. It does not require much time, some minutes.


Vtune works, as oyu can see from graph. Y are values in Hz from 10MHz reference, X are Vtune values.


To my eyes, everything seems to be fine.

Second test:
I put the oscillator back in the board and powered it up, monitoring Vtune, current and frequency.
Sorry for creepy graphs, but the code was made in a hurry, during lunch





I'm still monitoring the oscillator after a couple of hours.

UCCM >SYSTem:STATus?

-------------------------------------------------------------------------------
57964-15     serial number  86854165     firmware ver  3.0.0.11-01LINK    mode
-------------------------------------------------------------------------------
Reference Status __________________________   Reference Outputs _______________
XX Ref 8KHz 0: [LOS]
XX Ref 8KHz 1: [LOS]                          TFOM     7            FFOM      1
XX Ref 8KHz 2: [LOS]                          UCCM A Status[OCXO WARMUP]
XX Ref 8KHz 3: [LOS]
>> GPS: [phase:-1.4E-02, settling]
ACQUISITION ...................................................[GPS 1PPS Valid]
Tracking: 10 ___   Not Tracking: 1 ________   Time ____________________________
PRN  El  Az  C/N   PRN  El  Az                GPS      13:57:56     08 Sep 2021
  1  13 158   36     2  14 320
 22  25 107   41                              ANT DLY  0 ns
  4  72  44   42                              Position ________________________
  3  43  95   42                              MODE     Hold
 17  12 229   37
  9  65 252   44                              LAT      N  43:35:11.823
 19  21 251   38                              LON      E  13:31:1.253
 26   6  64   39                              HGT              +225.60 m (MSL)
  6  47 302   43
  7  20 181   41

TFOM is still very variable, while Vtune is stuck at 1.54V, so it seems to me that no attempt is made to "tame" the oscillator.

Do you have any idea? Is the oscillatore gone? Is the board faulty? Still having a loto to test.

Thank you for your attention!

[maskedviperus]

I'm still monitoring the oscillator after a couple of hours.

UCCM >SYSTem:STATus?

-------------------------------------------------------------------------------
57964-15     serial number  86854165     firmware ver  3.0.0.11-01LINK    mode
-------------------------------------------------------------------------------
Reference Status __________________________   Reference Outputs _______________
XX Ref 8KHz 0: [LOS]
XX Ref 8KHz 1: [LOS]                          TFOM     7            FFOM      1
XX Ref 8KHz 2: [LOS]                          UCCM A Status[OCXO WARMUP]
XX Ref 8KHz 3: [LOS]
>> GPS: [phase:-1.4E-02, settling]
ACQUISITION ...................................................[GPS 1PPS Valid]
Tracking: 10 ___   Not Tracking: 1 ________   Time ____________________________
PRN  El  Az  C/N   PRN  El  Az                GPS      13:57:56     08 Sep 2021
  1  13 158   36     2  14 320
 22  25 107   41                              ANT DLY  0 ns
  4  72  44   42                              Position ________________________
  3  43  95   42                              MODE     Hold
 17  12 229   37
  9  65 252   44                              LAT      N  43:35:11.823
 19  21 251   38                              LON      E  13:31:1.253
 26   6  64   39                              HGT              +225.60 m (MSL)
  6  47 302   43
  7  20 181   41

So I'm looking at your log - it still says its in ocxo warmup.  Is ur ocxo still warming up or does it think its not warm? Pretty sure when it says ocxo warmup its not gonna try and tame it.

[bitsandbobs]

Hi All
Just got one of these boards and attached a photo of the top side, as you can see it has no ocxo !!
anyone know of what make and type is used, also i have marked with a red square where i think
maybe some parts are missing !
Can anyone look over the photos and confirm if thats the case.

Thanks
Howard

[ZigmundRat]

Yeah, this is a snarky reply. Try to help yourself at least a little bit before asking to be spoon fed. Everything you asked can be answered by looking at page 4 of this thread.

[daddioo]

Hello everyone, I'm IW2HXZ, I have a Symmetricom with OCXO Oscilloquartz, I used Arduino Mega 2560 R3 with Display, the arduino program and all the assembly I downloaded from this site, thanks a lot to the creator of the program that works very well on Symmetricom, I bought a Samsung STP 2878 LF UCCM on Ebay, I have done a lot of tests and I have noticed that it is much more accurate than the Symmetricom. I ask if there is anyone able to modify the file to make it work with the Samsung UCCM, a small contribution would be available for those who are able to make the program work with the UCCM STP 2878 module. Sorry for the English, I'm using the Google translator.
Thanks Giuseppe

[ZigmundRat]

What is the problem? Does it not work at all? Or is the problem that the display shows Symmetricom and not Samsung? I think I have both units at home but I am moving house so I am not sure when I could look at this.

[daddioo]

Thanks for the reply, it doesn't work at all, maybe it's not compatible with Samsung.
Happy New Year to all
Giuseppe

[PE1DHI]

Hello fellow frequency keepers,

Here again a troubled hobbyist with a non functioning Symmetricom board.
I inspect the board on missing components and everything looks all right, no raw broken solder spots. It came without the TCXO and i placed a CTI TXCO on the board. Some warning is required for the "PWR"connection -> 12Volt. It can lead to confusion and destroy the TXCO.



I connected the TXCO direct to the 5 volt PCB supply, otherwise U1 could die by heat dissipation during oven-startup?
After preparing the PCB and monitoring.
After 2 days no lock. The Vref tries regulating between 0 and 2.6 volt. The TXCO is more or less jumping between -8 to + 11Hz. When monitoring with Lady Heater I see this:





It seems that GPS reception is sufficient enough, but no locking TXCO.

Anyone a idea how to handle this?  Ready to listen...or is it time to abandon this PCB?

[PA0PBZ]

Could it be that the EFC works reversed on this TXCO? The wildly jumping DAC value seems to imply something like that, the poor thing is unable to lock. I can't remember if it should be voltage up = frequency up but it is mentioned here a few pages back.

[PE1DHI]

Could it be that the EFC works reversed on this TXCO? The wildly jumping DAC value seems to imply something like that, the poor thing is unable to lock. I can't remember if it should be voltage up = frequency up but it is mentioned here a few pages back.

Hello Paul,

I already thought on that and did connect en 1:1 voltage inverter opamp. The strange thing is that when I decouple the Vref from the TXCO, the voltage from Vref is steady 2.6Volt. Not a trace of any regulation. Even with the inverting opamp the Vref does not show any change? Vref can not handle a load <1M ohm I noticed. It look like a defect output buffer from the DAC?

The CTI TXCO has high Vref is high frequency .

Jugo

[PA0PBZ]

I just looked at your drawing again and I think I see the problem. the connection marked VREF (on the pcb) is the output of the built-in voltage reference and should have 5V on it, and you also marked the EFC as being ground. That's not going to work

[glosair]

Building my own at the moment and came across this thread.

Where did you get the distribution amp as I'm probably not using the correct search terms...

thanks in advance.

[PE1DHI]

Building my own at the moment and came across this thread.

Where did you get the distribution amp as I'm probably not using the correct search terms...

thanks in advance.

This HAM makes them for a low price:

https://telecom.tweedehands.net/accessoires-diversen/10-mhz-distributieversterker-1-10.html