First Satellites with the FCD

While I’m still combating front end overload with the FCD, a simple 2m/70cm duplexer goes a long way when using my discone. Nevertheless, I managed to get:

• HRBE. I have previously noticed is rather easy to receive. HRBE was known as Explorer 1 [Prime] Unit 2 before launch.
• RAX-2 (I think). Only got a single packet, but it was strong and in the right place, with some doppler. It was near overhead, and going north – maybe it was commanded by SRI (one of its commanding stations) took it out of beacon mode and into a downlink mode that I don’t have the gain to receive.
• CO-57
• CO-55

I tried RS-30 with my QFH & preamp, but it is too sensitive to QRM and just makes a mess of the spectrum.

For reference, I’m still using the frequency correction I’m using right now is 1,000,014/1,000,000, that I determined with my FT-817. While I will be refining the tuning with the soon-to-arrive FT-897 that the school club has purchased, the accuracy does seem to be quite good. I.e. if I set the FCD LO to the natural frequency of the satellite, it enters that blind spot around the TCA! Obviously in the future I will put the LO deliberately off frequency, but for now, with uncertain frequency knowledge, I wanted to give myself the best chance of seeing something at all.

More Acer Aspire 5532 upgrades

Upgraded the CPU again, from the 1.8GHz TL-56 to the 2.3GHz TL-66 ($35 on eBay). The only thing higher that is compatible is the TL-68, but the extra 100MHz isn’t worth the price premium. This improved my Windows Experience Indexes from 4.5 to 5.3 for CPU and 3.0 to 3.2 for Aero graphics. RAM held steady at 5.9, as did graphics at 4.6 and disk access at 5.4. Memtest passes with flying colors, which also exercises the CPU and chipset a bit thermally.

I’ll be ordering the 5.8Ah battery – the TL-56 already makes for quite a short life (annoying for mobile radio work), and the TL-66 burns a couple more watts. And somehow the battery capacity is already at 70% of the advertised 4.2Ah (although I didn’t keep track of it like I have been on my MacBook).

Temp wise I think the fan is running harder now. SpeedFan reports a 53C idle temperature.

Also left the system running Windows 7 / Ubuntu 10.10 dual boot, but the Windows installation failed in December, which was followed by a maddening inability to reinstall using the recovery DVDs. I ordered new ones from Acer, and those had the same problem. After looking at the log it would fail decompression, but on different files with each attempt. So I ran memtest86+, and volia! Bad RAM makes for bad files. Fresh 10.10 Ubuntu installation too, so things should work swimmingly.

So, with the ram already at 4GB only possible upgrade left to do is a SSD, but it is tough to squeeze a dual boot into that amount of space. It may help to leave a SD always installed for documents. The slot supports SDHC, but not XC, which tops out at 32GB.

I use this laptop mainly for work (GSE, rdesktop to other workstations, meetings/presentations, trips, etc). Generally it is the  ”3rd monitor” on my desk when combined with Synergy (which is awesome). This laptop is also handy when I need either Linux or Windows portable (ham radio / SDR / satellite work).

My intro to SDR: The FunCube Dongle

I have a new toy, the FCD, which is a software defined radio receiver. It is all in one unit the side of a large thumb drive, so sound card wiring, messing with audio levels, drivers, etc are non existent. I’ve been grappling with two problems – first is frequency calibration, and second is sensitivity.

After letting the battery in my FT-817 go dead, and losing the DC cable for awhile, I had no trustworthy transmitter to determine a frequency offset with. I mean, was I really going to rely on local repeaters, with the FM capture effect being able to accommodate rather large tuning errors? Finally I got my power cable and did a small CW tone, but of course proximity made a defense and created multiple signals in the waterfall. Finally I found the right one, which results in a frequency correction off 1,000,014 (the unit shipped with 999,855, a 158ppm difference).

I started with WRPlus, which is recommended in the FCD tutorials, but I found the layout poor, and more importantly the program started becoming unreliable and crashing. Granted, this is running on my Acer Iconia Tab W500 (new to me, but relatively underpowered with its C-50 processor), but HDSDR seems to be doing a much better job.

Second, and a common problem, is that the FCD is relatively deaf. The FT-817 is much more sensitive in practice. The FCD has no front end filtering to speak of, and therefore is prone to de-sense in high RF environments (LA qualifies!). I’ve been trying to accomplish the same satellite receptions that I have already listed on this blog (same antenna), with no success yet. Looks like I’ll need to invest in some band pass filters…

I should also note that I am running firmware 18j. 18i was giving me periodic stuttering in the waterfall that I thought was just a CPU resource issue, but it persisted after I stripped out all background processes.

I also signed up for the FCDeveloper group (in addition to the normal FCD group), so that I could get my hands on FCHID008, since it seems to be the only controller with an option for the FCD’s bias tee. The bias tee is great because it allows me to I can conveniently use my new quadrifilar helix antenna. It is quite apparent that the antenna’s preamp is working, but I have not attempted satellite reception with it quite yet.

Lastly, while the FCD is supposed to be multi-platform, the QT based controllers simply crashed on my Macbook (running Snow Leopard if it matters), and the forays into gnu radio will have to wait for another day (and all the other applications seem far too dated to put in the dependency-hell effort).

Fix Time Machine Sparsebundle NAS Based Backup Errors

I still use my old MacBook 2,1 routinely, and thankfully I’ve been using Time Machine to keep all my data safe. I don’t use a Time Capsule (too expensive, too closed, and no redundant hard disk), but I do use a Seagate FreeAgent GoFlex Net (successor to the Dockstar), otherwise known as a STAK100. It is running Debian, with a pair of mirrored 500GB disks.

I recently got the following prompt:
Time Machine completed a verification of your backups. To improve reliability, Time Machine must create a new backup for you.

Which meant my old backup was going to get deleted!

I disabled Time Machine while I figured out what to do. Thankfully, Garth Gillespie documented the recovery process quite well in this post.  Basically, the Mac had to perform a thorough fsck on the backup sparsebundle, and I had to change some flags in an XML file. Simple but lengthy process. I let it run overnight (on gigabit, as suggested). Thanks Garth!

Guest VLAN w/ Linksys E3000 & TomatoUSB

I decided to upgrade my router to dual-band N, mainly so my backups could be done quicker. I settled on the E3000, and loaded TomatoUSB on it. It was a mostly seamless transition, with only a couple caveats:

• It consumes considerably more power than the WRT54G-TM it replaced, so much so that I could no longer use with my Cyberpower Phonesaver (a kind of mini-UPS that only outputs DC, designed for cordless phones) to back it up. I’ve since settled on a standard, albeit small, UPS.
• It runs a bit warm, so I placed standoffs underneath it to improve ventilation

So, the WRT54G-TM sat unused for a few months, until the rediculous requirement came about that, for a particular Nintendo DS game (Animal Crossing Wild World), I had to setup a WEP access point! Therefore, a secure and isolated guest network was necessary. A similar setup exists at my parent’s house to support the same game.

I used the following guide, along with this, with the following changes would be required to support the E3000:

• vlan2 is used as the WAN, so this guest network has to be created on vlan3
• The port assignments start with the WAN as port 0 (backwards from the WRT54G), therefore, the port furthest away from the WAN port, which will be used as the guest network port vlan3, is port 4
• The CPU on the E3000 is port8, not port 5 as it is on the WRT54G
• The init script needs to refer to vlan3, not vlan2
• The firewall script needs to refer to vlan3, not vlan2, and on the 2nd line where vlan1 is mentioned it needs to read vlan2
• The DHCP configuration needs to refer to vlan3
• The first QoS rule is anything from the vlan3 subnet is defined as the lowest priority
• Assign a static DHCP address on the main router for the guest router’s WAN address
• Forward an arbitrary range (I’m trying a mere 10) of UDP ports to guest router so said game would work.

The guest router is setup relatively close to the main, but they are separated by a couple meters in an effort to reduce interference. I used the following settings:

• Low TX power (10mW, may be reduced further)
• Ch11 (my main is channel 1, so there shouldn’t be any interference)
• It is also set to be B only (no G, no mixed)
• Basic Rate of 1-2Mbps
• Transmission Rate of 1Mbps
• No telnet, ssh, and wireless web admin access
• remote admin access with https enabled
• MAC filtering to only allow the Nintendo 3DS in question
• Static DHCP address assigned to 3DS
• 3DS’ IP address is setup as the DMZ

You will note that several settings on the guest router (in addition to the QoS on the main) are specifically to reduce available bandwidth. This particular game consumes very little, and the limitations serve to discourage anyone who took the small amount of trouble of hacking WEP & MAC filters from sticking around to leech bandwidth. These days it could be cracked in under a minute. The reduced bandwidth may also aid in reducing the TX power level even further, since the smaller the footprint one broadcasts the less likely you’ll be seen to begin with. In the same spirit of reduced footprint, the router is off most of the time, and only turned on for the game via those convenient remote power outlets that run on 433.92MHz.

With the NAT rules presently on the main router, the guest router can only be reconfigured with some SSH port forwarding via the router or by physically plugging in a laptop to the guest lan.

This “animal crossing” router can easily become a more generic “guest” router by disabling the MAC filtering, boosting the TX power, removing the bandwidth limitations, and changing the security to anything-but-WEP since 26 character hex strings are extremely unpopular.

More Satellite RX

With my CAT interface setup (along with hamlib’s rigctld and gpredict feeding the Doppler data) I’ve begun trying out more satellites.

Today I heard:

• AO-51 voice repeater
• CO-57′s CW beacon
• HO-68′s CW beacon
• COMPASS-1′s CW beacon
• CO-65′s CW beacon
• RS-22′s CW beacon

Satellites I tried but did not hear

• O/OREOS’s packet
• SO-50′s FM repeater
• FAST-1
• CO-65′s packet
• UWE-2′s 1k2 packet
• ITUPSAT 1
• BEESAT

I’ve noted that on these passes I’m still severely limited to the north/northwest due to building layout. I’m considering the following to help:

• Extend my antenna mast a couple more feet (and add guy wires to improve stability)
• Trying out some preamps like the Ramsey PR100 (2m) and PR40 (70cm)

I’ve also noticed that when I’m in CW,CW-R,LSB, & USB modes I hear clicks associated with the CAT interface, which is sending new frequencies at a configurable rate (gpredict’s default is 1Hz, I’m using 5Hz successfully, but the clicking does correlate with there rate). Changing the CAT baud rate from 4k8 to 9k6 or 38k4 doesn’t seem to make a difference.

Satellite RX

I’ve managed to hear the following so far with my setup:

• ISS packet (2m)
• ARISAT-1 voice tlm (2m)
• RS-30 CW beacon (70cm)
• HO-68 CW beacon (70cm)

I can’t wait to get auto doppler tuning and begin decoding!

Apartment QTH setup

I finally have enough equipment to setup a amateur / ham radio station at my apartment.

Interior:

• FT-817ND all mode HF/VHF/UHF transceiver (5W) w/ CAT cable
• BD-35 VHF/UHF amplifier
• 1GHZ VIA mini-ITX computer, equipped with 12V Powerpole outlets

Exterior:

• 8ft aluminum extendable tent leg (military surplus)
• D-130NJ discone antenna (6m, 2m, 70cm TX) @ ~16ft above ground
• 15ft N to PL-259/M/UHF LMR400
• lots of zip ties to attach to a 1″ square metal fencepost.

So far I’ve managed to get 11 repeaters from 6m to 70cm, but that was with a 50ft run of RG-58U (4.2dB loss @ 400Mhz, 1.9@100, 1.3@50). This short LMR run is a mere 0.35dB @ 400, so ultimately I should be going from ~10W output to ~30W.

I’m going to assess the performance over the coming weeks, and if my ability to hit campus remains lackluster I’m going to add an additional 7ft to the antenna height by adding another aluminum tent mast and u-bolting them together. That should put it slightly above the roof line of my building (but sadly still well below the neighbors to my immediate north and south).

Other equipment:

• Lead acid battery / jump starter
• DJ-580 (APRS/packet duty)
• MFJ-269 HF-UHF antenna analyzer

Additionally, portable:

• TH-F6A w/ semi-permenant SMA to BNC adapter & CAT cable
• law-enforcement-style earpiece and lanyard
• RH-205 telescoping 2m antenna (9.1″ stowed, 52.8″ extended)
• VX-3 (XYL’s)

Macbook SSD

Dropped my MacBook. Hard drive is dead – nortorious constant clicking. Too bad my backups are way out of date… I have to setup Time Machine again.

 

Anyways, I took this as an opportunity to upgrade to an SSD. Grabbed an ADATA AS599S-64GM-C RT off of Newegg for $140. The advertised rates are always exaggerated, but with Blackmagic Disk Speed Test I clock in around 140MB/sec read and 110MB/sec write. Still no slouch.

Is there anything left in my Macbook that I haven’t replaced?

Fresh Windows install aids

Two aids that make installings Windows (almost) bearable: ninite and autopatcher