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Re: CAT Interface: Hamlib Library Interface
I created a Dropbox folder for "work in progress" type material, and uploaded my current hamlib alpha-testing directory. Let me know if you don't receive and email invitation ...
fldigi has a number of different CAT method options built-in supposedly, including hamlib. However, I was unable to get it to connect via hamlib to the FT-980. I'll try again. flrig appears to be closed-source, which is a potential issue (have to convince the developers to assist if the base code needs to be modified. The rig description files are .xml-based, which helps ... but the FT-980 has a particular quirk that could be a problem. The FT-980 CAT system uses an echo back PLUS an "execute" command, in addition to the command. While a few other rigs seem to have the "echo-back", the "execute" command seems to be unique. 1. PC -> Rig: Command 2. Rig-> PC: Echo-back 3. PC-> Rig: Execute If the flrig base code doesn't support both the echo-back and execute quirks (so we can just create the .xml file), then we would need the developer support. But first things first for me: I'm going to concentrate on hamlib (fix bugs, add functionality). What is really intriguing is the rigctlcom program (TS-2000 translator) that might even help workaround fldigi/flrig. -- -Mat Breton, N8TW |
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Re: FT-980 Used with a transverter - frequency display to suit VHF / UHF band
Hi Phil,
Inrad sells a 6th-order 47.055MHz crystal roofing filter meant for the FT-980, but I don't know anyone who has installed it (and certainly no one who has done pre/post testing to see effects on sensitivity). Cost is $125 (plus S&H), and it is currently in-stock. I will include some details in the "mod" files folder. Give me a couple hours ... Note: You will almost certainly limit FM bandwidth to 5kHz (vs the 12kHz native bandwidth). While the initial tolerance of the matched crystals will likely be good, I'm not so sure how a VHF filter is going to behave over time as the crystals age. At 47MHz holding a 5kHz band requires VERY closely matched crystals. -- -Mat Breton, N8TW |
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Re: CAT Interface: Hamlib Library Interface
Update: progress is slow since I work during the day, but this is still moving forward.
I've been making a linux? Since I didn't want to add another PC to the mix, I decided to dual-boot my shack PC. I purchased two 256GB SSDs, reinstalled W10-64 on one and put Ubuntu on the other. Configured grub2 as a triple boot for now (Ubuntu, Old win-hd, New win-ssd) until I can get everything copied over/reinstalled/reconfigured on the Windows half. Lesson learned: make a "backup' through TSQL of your TSQL certificates. They are "married" to your PC config and you can't copy them over. You need to use TSQL to make a special backup, copy the backup over, and then restore from the backup. Good to know to keep a backup copy JIC you ever lose your PC/laptop.
Tomorrow I'll load the necessary programs (Git, GCC, astyle, etc) and files to compile hamlib. I'm thinking of using "Atom" as my IDE (development environment) ... I'll give it a go at least.? That is it for now. -- -Mat Breton, N8TW |
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Re: 4 files uploaded
#file-notice
It was a draft doc in case I ever got around to trying this out. Just a bunch of notes on VHF roofing filters, things to watch for, etc. No one else would understand the stream of consciousness writing style except me :)
Much better: read AC0C's nice presentation on roofing filters:??. He has a couple pages on VHF/upconversion architectures. There may be unintended consequences of installing this roofing filter in the FT-980. For example, the inrad filters have a measurable insertion loss (as you'd expect from a 6-pole filter), and no onboard amp to compensate. The result is that you are depending on the AGC system to compensate for this loss by increase the gain. Since the FT-980 AGC wasn't specifically designed for this, I'm not if there are any negatives beyond the obvious. I would love to see before/after results on certain things like receiver sensitivity, blocking, IMD3, etc. This would be a good way to tell if the mod is a net positive or no. These are some efforts to do just this on other radios to varying degrees: -- -Mat Breton, N8TW |
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Re: CAT Interface: Hamlib Library Interface
Had a great evening:
1. Got git working (git is the distributed/team source control system that is used). Created my own fork from the origin, cloned that repository to my PC, created a branch, fetched updates (these are all terms and processes that I have just become familiar with).
2. Got the GCC toolchain working: bit of a struggle on this one, as the developer's instructions are a bit out of date to the actual code. A bit of reverse engineering requiring, but I got it compiled and working.
3. Fixed the bug I found in the Alpha code
4. Submitted it back to github hamlib origin with a pull-request, which was accepted by the team. It will appear in the next tarball release (or you can get it now if you want to compile it yourself)
Summary: I can now make changes to the hamlib FT-980 backend and submit them to the open-source project. I also wrote the instructions and can pass them along to anyone else who wants to. Onward and upward: I will now be starting to add new features to hamlib. These will start appearing to the general public when official releases are done (at least twice/year). -- -Mat Breton, N8TW |
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Re: FT Newsletters Product Detector upgrade
I've always found these diode-type articles interesting, and have wanted to actually take some before/after measurements. I found the QST article in the FT Newsletter that discussed this change as having a better low-frequency (AF) distortion (thanks for pointing it out!), although the FT newlsetter also mentioned lower audible noise. Both were anecdotal and didn't give any testing results or other evidence.
The 4082-2900 was HP's MPN for a 1N5711 Hot-Carrier Diode. You could buy them in "matched" lots. Do you know if there were any differences to a general 1N5711 part? Note: if you are looking for a "lower noise" mesh-diode, the HP 5082-2903 was likely "screened" from general 1N5711 production for 1/f noise.
Back in the 60's and 70's HP's semiconductor division made some parts that no one else in the world did at the time for their test & measurement group, as well as general sale. But they spun it off with Agilent, which split it into Avago, which then merged with Broadcom. A lot of the old specialized parts are not available anymore (try to find a matched pair of detector diodes for a classic HP spectrum or power analyzer). But like capacitors, technology has moved forward from that period. I suspect there are even better diodes available nowadays.? Certainly for mixer diodes (nowadays more likely to be passive MESFET mixers). Please keep us updated: this one is really interesting to me ... -- -Mat Breton, N8TW |
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Re: FT Newsletters Product Detector upgrade
Would it be possible for you to take before and after audio noise floor and signal measurements? I *think* it could be done with an HF signal generator and an audio analysis program on a PC (I would recommend?DL4YHF's Spectrum Lab because it already has noise floor and peak detection built in ...?).
I've never seen this done with any of the germanium->silicon diode replacement articles, and the guy who did the FT-980 mod took no measurements whatsoever.? This would be relevant to all sorts of older rigs, not just the FT-980 I think; if the passivation creates enough noise to show up in the 8mV (typical) signal level at Q3038, I think it has application in other rigs as well. If done carefully, this might be the basis for a QST or QEX article ... -- -Mat Breton, N8TW |
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USB-CAT Cables: A question for anyone ...
This is for the hamlib CAT library improvement project.
Do any of you have one of the USB <-> FT-980 CAT cables (not a FIF-232C interface)? If yes, do you know if it supports PTT (through CTS/RTS pins)? If yes, is it the CTS or RTS? The FIF-232C does support the (you need to add a simple circuit to tie the RS-232 pin to the CAT pin), but since the CAT port does support it I suspect that they may have this support built in. I would like to make sure we define the library to natively support these cables ... Thanks, -- -Mat Breton, N8TW |
Mat Breton N8TW