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Thread: Recapping 4 Astro Spectras

  1. #1
    standardmissile No Longer Registered

    bang Recapping 4 Astro Spectras

    Hey, I have four of these little ba***rds to recap and I have been told a few ways to do it. I plan on replacing the shot/dying Aluminum Electrolytics with some higher quality ones from Mouser Electronics. In the past when I recapped my dad's Sony rear projection TV and my car stereo I always used Elna SILMIC II capacitors, as they seemed to do wonders for both cleaning up the video/audio in the old units. What type should I use in these buggers, aside from probably upping the voltage limitation to allow for longer life, and not using cheap caps from china (see badcaps forum)? I heard Panasonic HD, Elna SILMEC, and and pretty much Nichiocon anything are decent as far as Aluminum Electrolytics go.

    Also I would really like to know what caps are the ones in line with the RF signal and anything touchy DSP/Signal Filter/Mic/Speaker vs PSU/general stabo units. That way I can go all out and install high quality components in where they would have the best chance of improving Tx/Dx audio quality/strength.

    My rationale is that I'm giving one of these to my dad who's retired Marine, and former PD, so really want to make it shine for him, since he wrapped up his career with the force just as Astro Legacy equipment was entering service. Plus its a way for me to spend quality time chatting with him since I live far enough away that I can't visit regularly, but can still reach him with a VHF 50-110 watt HAM.
    Last edited by standardmissile; Jan 02, 2013 at 10:33 PM.


  2. #2
    Will No Longer Registered

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    I still do the refurb and only use Mil spec parts. One year warranty on my work.

    There is a couple of component value/type changes that are not documented. One makes the Astro Spectra sound good like the good old regular Spectra.

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    Almost none of them are anywhere near RF circuitry - 'lytics are large value caps for the most part, that are used in noise filter and DC blocking "capacities". (groan)

    That said, there are a few on the RF board that might be somewhat sensitive, but most are in common usage applications, and run of the mill, garden variety parts will be fine. I have seen several modified using Tantalum orange drop caps, so pretty much any cap will do.

    However, better is better (?) - if you use a higher quality of cap, it can't hurt, 5% parts would be 'mo betta than 20% parts. If you are planning on using the radio in a mobile application, mechanical considerations should be taken into account - you may want to source the same physical form factor parts to maintain shock-resistance specifications.

  4. #4
    standardmissile No Longer Registered

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    Hehe... Will I work with MiSpec parts for a living, and I can tell you they often make much more rugged components in civilian specs with craploads more quality. MilSpec is just so that some "Dips**t" PFC can drop something off the back of a 5 Ton out in the middle of The Stumps and come back a day later once his SSgt grilled his ***, and have whatever not be completely f**ked. The best radio I ever used was a civillian Yaseu HAM that was tuned by my buddies dad who worked for General Dynamics before he retired. I swear you could talk to people 600+ miles on the 144-148 VHF band and have it sound like they were next door on the telephone, without a repeater.

    However I am interested in the implied quality of the audio coming out of the work you do. However I have never heard an old analog spectra, so I cannot actually make a good evaluation based on the comparison. Do you have an audio sample while operating in FM, FM narrowband, P25, and just for giggles n' ****s CVSD Securenet?

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    Yeah, a buddy of mine told me he got to visit a "listening post" for a three-letter agency and said he was surprised as hell to find a roomful of Icom stuff!

    I don't have samples of the analog spectra handy but it has very similar audio circuitry as the Astro Spectra, or the old X9000, they use the same time-tested mobile speaker design, which accounts for a lot of the audio quality. As far as secure or digital processing they would be equivalent to an Astro Saber or XTS3000 but with 12 Watts of audio and a much better speaker...

  6. #6
    standardmissile No Longer Registered

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    Is the audio quality better on an Analog Spectra? Or is it just slightly better than the Astro Spectra?

    Reason I ask is that CVSD sounded metric craploads better on my Legacy Analog Sabers vs when I used the Astro Saber/XTS-3000. My partner at work put it that it sounded like he was "calling New York from LA, via Jallabad, on a party line," the audio was so crappy. At 12Kbit a second I don't blame his analogy, except that USA/USMC SINCGARS at 16Kbit sounds no where near as bad, and my old Analog Sabers example.

    However if you compare the latest USAF version SINCGARS at 32Kbit to Moto Securenet at 12Kbit or even APCO-25 IMBE it would be like pitting premium vinyl vs a 1990 Taiwanese Cassette deck IMHO.

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    It's about the same - in analog mode. You have basically the same bandwidth audio 300-3K, through approximately the same audio amp circuitry, played back on the same type of speaker/enclosure. I still think the audio PA circuitry and speaker/enclosure factors are the biggest reason the Sabers sounded so much better than the Astro's.

    Also, remember that APCO is a completely different animal, it uses a vocoder instead of attempting to reconstruct an arbitrary analog waveform D/A, it emulates the human vocal tract and delivers pre-recorded phonemes which it has to match carefully on encoding, but for playback it just has to play back samples in the proper order, essentially. I read somewhere the samples of speech are encoded at about 19 kHz or so. So the final audio, if the proper phonemes are chosen, can sound almost as good as a broadcast audio recording.

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    I can vouch for Will's work. He recapped a couple of Spectra's for me several years ago, which brought them back to life. GARY

  9. #9
    standardmissile No Longer Registered

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    I just opened one of these bad boys up today, and it looks like there is an IC board in there with a heatsync. Great, looks like a new set of thermal grease goes into all of these buggers too lord knows how dry/crusty that stuff is by now.... How much does Will charge for his recapping service, and what services does it include, and types of components are used as replacements? Feel free to PM me any info if need be.

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    If you are interested in learning more about recapping Spectra radios, take a look at this link. I recapped my 900 MHz Spectra a couple of years ago and it was fairly easy:

    http://www.ai4ji.com/Projects/Spectr...e-cap_kits.htm

    This person will also recap them for you. He charges $50 per radio.

    Here's another good source of information:

    http://www.repeater-builder.com/moto...ctra-caps.html

  11. #11
    standardmissile No Longer Registered

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    Those Aluminum Electrolytics on his web page are essentially the same shoddy ones I've seen at work. According to our service techs at the repair depot, they need to be inspected at 500 operating hours and every 100 hours after that using a special UV light to detect leaking electroytic, with a complete replacement of said components at around 800 hours. Standard practice is to usually replace those buggers at the depot with Panasonic radials with a 105 Celsius heat range, and a non-conductive resin as to protect against high frequency/intense vibrations in the field. With that policy we pretty much just replace the caps at 1-1.2K hours for good measure, and never had a problem since.

    Also since we started that unofficial policy, we have had some of out equipment operate well beyond what the manufacturer claimed. For example, we had a portable manpack sized satellite transceiver that worked okay for communications way out in the field (where VHF and HF were difficult/cumbersome), however when the techs recapped it with the new Panasonic components (and a few SILMECs I had in my truck that day) the thing could bring in a signal even, if it wasn't properly aligned on the bird like it needed to be before. Plus we had about a 2% decrease in latency, and 7% increase in throughput on our data bus on average, when it was dialed in properly.

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    Quote Originally Posted by standardmissile View Post
    Those Aluminum Electrolytics on his web page are essentially the same shoddy ones I've seen at work.
    I agree with you on that point. The links were for informational purposes, and to provide a resource for recapping Spectras. I have always used tantalum capacitors when recapping, since I have had considerable experience replacing leaking electrolytics in vintage computers and found that tantalums are well suited as replacements. I recapped my Spectra with tantalums.

    In the trivia department, you can search the Internet and find interesting information about why the capacitors from that era leak (e.g., that the formula for the electrolyte was stolen, that the stolen formula was incomplete, and the the incomplete formula found its way into an untold number of capacitors sold).

    By the way, if your equipment smells like your pet urinated on it, you probably have leaky capacitors (or should get rid of your pet). That's what boric acid smells like.
    Last edited by Number 6; Jan 10, 2015 at 07:24 PM.

  13. #13
    standardmissile No Longer Registered

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    Any reason to use Tantalum caps, and not go with Aluminum electrolytics? Other than the whole 15 year/1200 hour lifespan and the vibration issues.....

    I had heard from an old ham/stereo guy that Tantalums were not always a good choice, but rather were an adequate replacement for the risks/shortfalls of gen 1 (1970-1985) and cheapo (recent Chinese/Taiwanese) electrolytics.

  14. #14
    Will No Longer Registered

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    This IS really old information.....

    Quote Originally Posted by squeaky View Post
    If you are interested in learning more about recapping Spectra radios, take a look at this link. I recapped my 900 MHz Spectra a couple of years ago and it was fairly easy:

    http://www.ai4ji.com/Projects/Spectr...e-cap_kits.htm

    This person will also recap them for you. He charges $50 per radio.

    Here's another good source of information:

    http://www.repeater-builder.com/moto...ctra-caps.html

  15. #15
    Will No Longer Registered

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    standardmissle,

    I sent you a PM.

    Will

  16. #16
    Will No Longer Registered

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    Quote Originally Posted by squeaky View Post
    snip'd

    By the way, if your equipment smells like your pet urinated on it, you probably have leaky capacitors (or should get rid of your pet). That's what boric acid smells like.
    That is the hard part, removing that smell, actually the damage from the leaking capacitors, and making the circuit work again.
    Sometimes there is damage without the smell or obvious signs of capacitor leakage.

    Remember, the Spectras first hit the streets in the late 80'. And I was there. Still working on them.

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    I just recapped five of them.
    Not a lot a fun with the dirty corroded solder joints and smell.
    I spent a lot more time cleaning than soldering.
    Don't forget your control head if you have one.
    However, they all worked great after the recapping.
    I did use tantalum caps in one radio. (The one I am keeping)
    Common sense is Uncommon.
    You can't fix stupid, but eventually it takes care of itself.