The assembly went ok so then I headed on to install Mythbuntu (which I had decided to try first) from an external USB DVD drive. Installation of Mythbuntu was incredibly straight forward and as I had decided this was to be a quick test install I just gave the whole 1TB drive over to it and it created one big root filesystem. My plan is to reinstall later and create at least two filesystems, one root and one for recording data.
When it came to setting up the tuner card I chose the DVB-C option but it didn’t give any feedback as to whether it had discovered it or not. After a little playing around with the DataSource and Input settings it became clear it wasn’t working quite right. I started looking at the dmesg output and found the following:
[ 8.849587] Linux video capture interface: v2.00
[ 8.940190] saa7146: register extension 'budget_av'.
[ 8.940268] pci 0000:00:09.0: can't derive routing for PCI INT A
[ 8.940274] budget_av 0000:01:0e.0: PCI INT A: no GSI
[ 8.940320] IRQ 255/: IRQF_DISABLED is not guaranteed on shared IRQs
[ 8.940326] saa7146: saa7146_init_one(): request_irq() failed.
[ 8.940342] pci 0000:00:09.0: can't derive routing for PCI INT A
[ 8.940358] budget_av: probe of 0000:01:0e.0 failed with error -22
This didn’t look good. After a little more delving I remembered seeing something on the mini-itx.com website about PCI risers:
Notes: Dual Risers only work with certain chipsets and motherboards. These Dual Risers are designed for boards with VIA C3 / C7 chipsets (i.e. most EPIA / Jetway boards), and with Intel Atom motherboards. To use with an Intel Atom board: put the IRQ jumper on the lower row, 3rd pair from the left. Untested / not compatible with other socket based Intel / AMD motherboards. We cannot guarantee compatibility with dual risers and all products.
Although it didn’t mention my motherboard or chipset I decided to take the motherboard out of the case and inserted the tuner PCI card directly into the motherboard PCI slot and this time the dmesg output looked much better:
[ 9.813798] saa7146: register extension 'budget_av'.
[ 9.814819] ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 18
[ 9.814831] alloc irq_desc for 18 on node -1
[ 9.814837] alloc kstat_irqs on node -1
[ 9.814855] budget_av 0000:01:05.0: PCI INT A -> Link[LNKA] -> GSI 18 (level, low) -> IRQ 18
[ 9.814909] IRQ 18/: IRQF_DISABLED is not guaranteed on shared IRQs
[ 9.814957] saa7146: found saa7146 @ mem f9b58c00 (revision 1, irq 18) (0x1894,0x0022).
[ 9.814973] saa7146 (0): dma buffer size 192512
[ 9.814980] DVB: registering new adapter (KNC1 DVB-C MK3)
[ 9.853549] adapter failed MAC signature check
[ 9.853558] encoded MAC from EEPROM was ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff
[ 10.117418] KNC1-0: MAC addr = 00:09:d6:6d:91:0f
...
[ 10.504977] DVB: registering adapter 0 frontend 0 (Philips TDA10023 DVB-C)...
[ 10.505476] budget-av: ci interface initialised.
Mythbuntu then gave some feedback straight away when I choose the DVB-C tuner card and it would search for channels.
The PCI riser did have a very long jumper on it.

I tried all the different jumper settings, one of them gave a slightly different result in dmesg but there were a lot of timeout messages for the saa7146 device.
I gave up trying to get the two slot PCI riser to work as I don’t need the option of two slots and have ordered a PCI riser ribbon cable from ebay which I hope will solve my problems.