MiniTiouner over USB EXtender

[W6BDD]

Greetings.

My MiniTiouner is reading about 37% on the USB / I2C over a short USB cable. It was suggested I get a LINDEY USB cable. I bought one. The response is worse. it went down to about 13%. I went back to the other cable at it again reads 37%.

i plan to place the receive and antenna about 100-150 feet away.

Has anyone had success with USB Extenders? RJ45 or Fiber?

If so, what make / model is recommended?

73's.

George Blake

[g0mjw]

Hi George,

1 - What's wrong with it reading 37% if it still works

2 - If the I2C is erroring, it is much more likely to be a problem on the I2C side and not the USB side. For example an OLED adapter, the wrong termination resistors fitted etc.

3 - If it is the USB side, it is entirely possible to have a different USB problem not related to the cable, try another PC, or perhaps you were unlucky enough to receive two bad cables.

Not tried a fibre/ethernet USB extender. I have tried an active cable USB. They seem to work but suspect if you are looking at fibre then the typical length up to 10m-20m or so plus a bit for the end cable, is further than these support. I don't know if you can daisy chain them. That might work. However, I would use a filtered preamp at the antenna and keep the tuner in the shack.

Mike

[W6BDD]

I bought the DATV receiver USB interface module along wit hthe other parts from BATC. I installe Resistor they said to add from the modification sheet. Maybe it needs to be re-programmed?

It appears to work fine even if it says 37%. However, extending the USB will probably add to the instability.

I am running about 120 feet maximum, so I could use USB to Ethernet or USB to Fiber. I would think that the Fiber would be a better choice for data degradation.

73's.

[g0mjw]

George,

The I2C termination resistors are not on the module, they are on the main PCB. R4 and R5, both should be 3k3. The I2C doesn't carry any of the image data, it is used for configuration and monitoring. The minitiouner is not designed for nor intended to be used with high symbol rates, if you are trying to receive broadcasts then perhaps the USB lead is overloaded, but for normal use it shouldn't be an issue. If it is working, then it is OK.

I would very very very very very very strongly advise using a coaxial cable to the antenna and keep the tuner in the shack. It will be much easier to deal with. A pre-amplifier and a band pass filter will be required, otherwise, unless you live miles from any other transmitters the many other RF signals around will be sure to cause issues.

Mike

EDIT - Apparently the I2C from the module is generated with the wrong type of output stage using bit banging. The I2C can be improved, as long as you don' connect any other bus mastering devices, with a suitable bodge. Pull up resistor for SCL is removed. SCL is driven by a push-pull output. The pull up is not needed and it slows the high to low signal transition. A 20 pF capacitor is added to SDA. SDA changes too soon after the clock edge, the capacitor slows it down. This might improve yours but it really should not be as bad as that. I have heard of faulty FTDI modules.

[Pa3fbx]

Or use the longmynd client and a remote raspberry loaded with longmynd and with all the network cable needed..
My remote/portable station is using up to 50 meter utp cable where the pluto, amplifyer, minitioner and an raspberry for control, monitoring, portforwarding, dhcp router, longmynd. all in 1 box.

The box is next to the dish for rx and tx...
Remote i use only pc...

Benno

[W6BDD]

Hi George,

1 - What's wrong with it reading 37% if it still works

2 - If the I2C is erroring, it is much more likely to be a problem on the I2C side and not the USB side. For example an OLED adapter, the wrong termination resistors fitted etc.

3 - If it is the USB side, it is entirely possible to have a different USB problem not related to the cable, try another PC, or perhaps you were unlucky enough to receive two bad cables.

Not tried a fibre/ethernet USB extender. I have tried an active cable USB. They seem to work but suspect if you are looking at fibre then the typical length up to 10m-20m or so plus a bit for the end cable, is further than these support. I don't know if you can daisy chain them. That might work. However, I would use a filtered preamp at the antenna and keep the tuner in the shack.

Mike

Nothing, except it indicates a poor condition and I asked about it and was told to try a Lindy cable. That was worse. I'm not really worried about it...yet. I haven't put a signal to it yet, so we'll see when I do that.

The USB port might be an issue. This PC is old. I have a Dell T-3500 Precision. The USB may be too slow.

[W6BDD]

George,

The I2C termination resistors are not on the module, they are on the main PCB. R4 and R5, both should be 3k3. The I2C doesn't carry any of the image data, it is used for configuration and monitoring. The minitiouner is not designed for nor intended to be used with high symbol rates, if you are trying to receive broadcasts then perhaps the USB lead is overloaded, but for normal use it shouldn't be an issue. If it is working, then it is OK.

I would very very very very very very strongly advise using a coaxial cable to the antenna and keep the tuner in the shack. It will be much easier to deal with. A pre-amplifier and a band pass filter will be required, otherwise, unless you live miles from any other transmitters the many other RF signals around will be sure to cause issues.

Mike

EDIT - Apparently the I2C from the module is generated with the wrong type of output stage using bit banging. The I2C can be improved, as long as you don' connect any other bus mastering devices, with a suitable bodge. Pull up resistor for SCL is removed. SCL is driven by a push-pull output. The pull up is not needed and it slows the high to low signal transition. A 20 pF capacitor is added to SDA. SDA changes too soon after the clock edge, the capacitor slows it down. This might improve yours but it really should not be as bad as that. I have heard of faulty FTDI modules.

The instruction sheet shows and describes adding a 10K Resistor from NC2 to the ground test point. They said it needs a pull down to work properly. That is what I added.

I have a 2-foot dish with a crossed dipole, then a 90 degree hybrid to convert back to circular polarization. After that are two LNA's and then right into the MiniTiouner. I have minimal loss and noise figure that way. I also don't have ot worry about converting 50 ohm output of the LNA's into 75 ohm input to the digital tuner. The dish sits on a box with the RF parts, which sits on a two-axis positioner to follow my target. It is better to convert to digital and then send it down.

[W6BDD]

Or use the longmynd client and a remote raspberry loaded with longmynd and with all the network cable needed..
My remote/portable station is using up to 50 meter utp cable where the pluto, amplifyer, minitioner and an raspberry for control, monitoring, portforwarding, dhcp router, longmynd. all in 1 box.

The box is next to the dish for rx and tx...
Remote i use only pc...

Benno

So, if I understand you, you have the Raspberry Pi at your Receiver / Antenna, and run an Ethernet cable to your shack computer? That would be better than trying to run USB. Ethernet is already set to run longer distances.

Do I run the MiniTiouner software on my local PC, or do you need another application? Will it identify the Ethernet service?

[Pa3fbx]

I am using 1 raspberry pi 3b (zero should work) with buster and no desktop OS.
First install firewalld for port forwarding.
Connect the pluto to the raspberry and see if you get the forwarding rules to work so you be able to use the pluto for your operations..
Next install longmynd as described on home site of ZR6TG and connect the minitiouner to the raspberry..
Get the longmynd client for PC from toms website. and make it working...
You need to do the portforwarding rules again.

Last install nodered to the RPI and make the controlling...

If you get stuck just call....

Benno