Make your own Astro Spectra

[xmo]

In the now closed thread: "900 MHz Astro Spectra", before it deteriorated into ham bashing, we were discussing the possibility of making an Astro Spectra that meets your needs out of some combination of Astro and Analog radios or parts.

For example - there are low range UHF Astro Spectras selling at low prices on ebay. The theory was that you could take an analog Spectra - maybe one you already have - that is on the right band and bandsplit - combine some of its parts with some parts from an affordable Astro unit to make yourself an Astro that meets your needs.

You can! I did it. It works.

What I had was a VHF analog Spectra and an extra 800 Astro Spectra. The 800 was P25 conventional only so it wasn't worth much in the world of 800 where everything is Smartnet or Smartzone. What I need is a VHF Astro mobile. I mixed the parts and made a VHF Astro Spectra.

Here is what you need to do it:
1. An analog Spectra of the correct range.
2. Any band of Astro Spectra so long as the host and DSP versions will support your target codeplug.
3. A codeplug file for DOS RSS that matches your desired final configuration.
4. DOS Astro mobile RSS, preferably R09.05.00
5. LAB S-record read/write capability & understand how to use it [DON'T ASK]
6. Astro Spectra basic and detailed service manuals.
7. If you are changing bands [as opposed to ranges] you will need surface component rework capability & some surface mount parts.
8. Programming computer with rib & cables.
9. Service monitor to do a complete alignment.

I started with the soft side of the project. I verified that the Astro & analog radios worked as they were. I verified the Astro Spectra host & DSP versions support P25 [as opposed to VSELP]. I read each radio and saved archive files.

I obtained a suitable codeplug for the target result. I loaded it into RSS and saved a clone file to match the target. I forced it into the Astro with S-records. The radio immediately said: FAIL 001 [which it should since it now thinks it is VHF but has an 800 VCO.

Then I shut everything down and disassembled both radios. The next step was to modify the RF board. I started by reviewing the list of components that change value from one band to the other. I listed these on a piece of paper. I then used a highlighter to ID those component locations on the service manual board layout. Then I changed all the parts to the right values.

It is not too hard. None of the parts are located under shielding. There was one jumper, one capacitor, and 6 resistors involved.

Once the RF board was converted - I assembled the Astro command, VOCON and RF boards along with the rest of the VHF parts into a complete radio. It worked immediately!

The leftover parts assemble back into an analog radio [800 in my case] which can still be useful for something. It will take some MLM hacking to get that going, but that can come later.

[tvsjr]

Very, very cool. What would it take to change ranges on a preexisting Astro? Say I had a 403-433 high-power Astro Spectra and wanted to make it cover the ham bands... full range 420-450 coverage would be nice, but just 440-450 would be acceptable. How would one go about making that fly?

I'm in need of a high-power UHF ham radio in the truck (my analog Spectra has leaky caps...) and going to Astro would be very cool.

[xmo]

Now you've got me thinking! I looked at the service manual. Officially Motorola sells these as 403-433, 450-482, and 482-512. The VCO application shows these as range 1,3, and 4 respectively.

That implies that there is a range two and, in fact, the manual contains the schematics and parts list for all four ranges.

I am guessing that the VCO is the most critical part - so I think what I would do to start would be to convert the range one VCO to a range two by changing the right parts and see how close that is to making a 'ham band' range two radio!

I may be shopping on ebay!

[tvsjr]

Officially, there is a Range 2 - 438-470MHz, but *only made in a motorcycle configuration*. I have utterly no clue why, but I digress.

I've got a spare Q-split 403-433 Astro Spectra. I've also got a 438-470 UHF motorcycle 15-watt 438-470 analog Spectra.

Which components are *range* specific and which are *band* specific?

I may need to sit down and do a little service manual reading tonight. A 438-470 analog Spectra is good to 430 or so... you might be able to end up with a 430-470 Astro?

Hmm...

[motorola_otaku]

I actually have an Astro UHF conversion project going right now, which I posted about here.

The prefilter in the Q-split (403-433) radio drops like a cliff above about 438, so you'd definitely need to swap that out to do anything above 440. The PA will continue transmitting full power almost to 460, so that's not a problem either. Modifying the VCO should be doable as well, BUT the etched trace WILL NOT CUT with any knife I have access to. If you had a diamond-tipped blade that was maybe 1/8' wide, or could desolder the shield and get to it with a Dremel or something similar, then you could shorten the trace and probably push the operating range up to 450 and beyond.

The real problem lies in the codeplug. Right now, I'm not thinking the Q-split codeplug is going to work above maybe 438 or 440, even if the hardware will. Right now, my radio has the unmodified VCO and prefilter from a range 3 UHF analog Spectra (which stayed locked and received and transmitted to spec from 440 all the way up to 490) in it, and it won't receive below 450 or transmit below 460. And the receive sensitivity sucks. And best of all, you can't realign it because all the test frequencies are below the VCO's operating range. I had to go in & out of Service mode just to get the analog deviation back where it was supposed to be. And I have no Astro test equipment, so I have no idea what it's doing on IMBE.

So my conclusion is: see the first post. If you have the right prefilter and VCO and a good codeplug, the Q-split Astros are definitely worth a look.

[Cipher77]

To the best of my knowledge, A "true"range 2 vco is made for the european market. I actually had a true range 2 analog spectra that a friend of mine who worked in land mobile products down in Dallas/ Ft. Worth gave me. He had a couple of those shipped to him for testing some SP spectras about 10 years ago & snagged them before they went to the squeezer.

just my 2 cents

[FMROB]

What happens if the astro radio you are trying to make was last programmed with windows software. Can you force feed a DOS s-record into it?? Thanks, Rob

[xmo]

You don't even need the S-record process - if you have a previously saved archive file for your radio -the DOS RSS will put it back.

If the radio has been programmed by CPS - if you try to read it with DOS RSS - you will get an error message - "Codeplug Too New For Application" - so - you just don't read the radio.

You load your archive file into the RSS, connect your radio, and hit "Program". So long as the target radio's serial number and flashcode match the archive file - the DOS RSS will program the radio.

That fact is one reason you see people asking for codeplug files. Once you have a file that matches your radio [except for serial number] you use the RSS clone feature to write a clone archive file to disk with the serial number of your radio. Then you load that file back into the RSS and program your radio. The flashcode of the donor archive file must match the target radio for this process to work.

[FMROB]

Ok, So what happens if I don't have a saved archieve of the "new" astro radio, and it was programmed with windows.

Could I get a useable codeplug and dump it using the mehtod you described?

Thanks, Rob

[motorola_otaku]

Ok, So what happens if I don't have a saved archieve of the "new" astro radio, and it was programmed with windows.

Could I get a useable codeplug and dump it using the mehtod you described?

Thanks, Rob

If the flashcode and model number match, yes. The version of RSS/CPS is irrelevant.

Unfortunately for me, I'm changing bandsplits so a simple codeplug archive won't do it. So if anyone has an unpacked codeplug or S-record of any dashmount R-split W7, even a motorcycle radio, I'd much appreciate it if they could send it my way. Digital ID Display would be nice (the current codeplug supports it) but 100001-000000-7 is all I need. On the flip side, I'd be happy to provide a copy of the current codeplug (flash is 500008-000000-1) should anyone have need for it.

[jmr061]

Getting back to the topic of making your own astro spectra that is exactly what I am in the process of, although unlike XMO I have decided to use parts from a range 2 UHF analog spectra motorcycle radio rahter than rebuild existing vco's, rf boards, etc.

I am getting a range one hi power uhf astro spectra from ebay. I will be taking the VCO and rx front end out of it and replacing those items with the same from the range two analog spectra. This will give me operating range of 438-470 although in an above post someone states the range 1 PA will only go up to 460 but that will work fine for my present needs (although I am looking for a hi power range 3 PA board).

The biggest obstacle would be finding a proper s record for the radio. I have done some playing with a VHF s record I have and have changed some info in it and hopefully it will work. Then of course a full tuning of the radio will be in order.

Jason

[xmo]

It looks like what we need here is a DOS codeplug from a real factory range 2 radio.

[ASTROMODAT]

It sounds like the real goal here is to come up with an affordable P25 Motorola radio, particularly for Ham use on 2M or 440 MHz.

You might want to consider a new Motorola XTL1500 P25 radio that are now going for street prices as low as sub $900, and Yes, that is BRAND NEW for a Motorola P25 radio that is ASTRO operational. Remember, the IMBE uplift cost for an eBay ASTRO ready radio is now close to $900 alone, not counting the cost of the radio itself!

Although the XTL1500 does not currently support encryption (and I'm hearing that future models will), keep in mind that 97.117 strictly prohibits any sort of encryption for Ham use anyway.

Just a thought...

[xmo]

"It sounds like the real goal here is to come up with an affordable P25 Motorola radio, particularly for Ham use on 2M or 440 MHz. .."
_______________________________________________________________

Exactly and since I already had the pieces - you don't get any cheaper than that. I started with two radios and I still have two radios - just that they meet my needs better now.

The same thing would apply to combining a low range UHF astro and a range 2 analog - the resulting two radios would be more useful - the Astro for all around use and the resulting low range analog could be used as a link transceiver. Two for less than the price of one.

The real problem is - I'm going to want an XTL with the new head - and that won't be cheap. [Anybody want to start a pool as to when the first one shows up on ebay?]

[ASTROMODAT]

Xmo said: "I'm going to want an XTL with the new head ."

I hear you on that, but just make sure you get the new W7 LCD head and NOT the new LCD W9 head. We have both types (several of the W7's and just one W9, thankfully!) with our newest XTL5000's, and while the W7 is absolutely wonderful, we do not like the W9 at all. Everyone will probably have their own 2 cents on this, no doubt.

[batdude]

i see the value of aftermarket 403-433 astro spectras going thru the roof

and i see those 438-470 low power motorcycle drawers all the sudden getting VERY hard to find....


just a prediction



doug

[motorola_otaku]

i see the value of aftermarket 403-433 astro spectras going thru the roof

and i see those 438-470 low power motorcycle drawers all the sudden getting VERY hard to find....


just a prediction



doug

Only if the necessary R-split codeplug all of a sudden becomes widely available, I'd think. Right now, that seems to be the missing link.

Besides, Q-split Astros are overpriced as it is.. I paid $300 for mine. If I'd gotten one of the high-power radios, that would've been another $150+ for the cables and W9 control head.

[ASTROMODAT]

FYI, the 438 - 470 MHz analog only Spectra was limited to the motorcycle configuration, whereas the current ASTRO series Spectra includes the 438 - 470 split in the "regular" (e.g., non motorcycle) dash and trunk mount mobile lineup, albeit you are limited to 25 watts, max.

Keep in mind that the motorcycle Spectra was a 25 watt Spectra with its power output factory set at 15 watts so 1) the PA wouldn't fry in the fiberglass box, and 2) so it wouldn't run down the small motorcycle battery. Also, the motorcyle radio has the waterproof head, mic, and speaker.

[batdude]

i have a 50w astro spectra UHF 450-482 codeplug

and i might have a motorcycle 438-470 astro spectra codeplug too




doug

[WB5ITT]

I have IIRC range 3 Astro Spectras in my fleet....with the current codeplug and RSS, I have been able to program my radio on UHF ham 440 freqs...Power is 100watts but rcvr (on 442-444) is down but not too bad (about 0.3 or so uV)....my Kenwood TM742 still outhears it on the ham freqs.....is there a way to improve it? I have not bothered to open the case up YET ....but Im tempted to (when I get the time!)...
Chris

[The Pager Geek]

Replace the Front end with a range 2 version instead of your range 3.

tpg

[motorola_otaku]

UPDATE

I finally acquired an R-split codeplug, and that did the trick.. the radio now functions 100% identical to a normal mid-power dashmount Astro Spectra. However, I did end up having to swap PA boards; after dumping the R-split codeplug in, TX power up around 462/467 dropped to 12 watts. At a glance, it looks like moving the range 1 PA up to a range 2 shouldn't be hard at all, just move some components around and shorten a couple of coils. The power transistors and PCB layout are identical. Modification of the range 1 prefilter MIGHT happen.. looking at the bottom, there are some etched traces and components that could be tweaked to expand the operating range. An extension to 450 might be possible this way. (keep in mind, I have no Astro or Spectra service manuals to work with, so I'm just winging it)

The deviation did require some tweaking (it came out quiet in wideband mode, 3KHz max), but the receive and transmit were spot on; 40 watt TX from 440 to 490 and .21 mV squelch break from 450 to 482. Sensitivity was a little disappointing down towards 440 where it dropped as low as .30, but still plenty functional. I don't recall the analog Spectra donor radio being any better. As for IMBE functionality, the only testing I could do was with a Bearcat 796 scanner, and it decoded the audio flawlessly.

Not counting what I paid for the analog donor radio years ago, I have less than $350 in this project. It's definitely worth it if you can get all the parts together.

[techie]

FYI, the 438 - 470 MHz analog only Spectra was limited to the motorcycle configuration, whereas the current ASTRO series Spectra includes the 438 - 470 split in the "regular" (e.g., non motorcycle) dash and trunk mount mobile lineup, albeit you are limited to 25 watts, max.

Keep in mind that the motorcycle Spectra was a 25 watt Spectra with its power output factory set at 15 watts so 1) the PA wouldn't fry in the fiberglass box, and 2) so it wouldn't run down the small motorcycle battery. Also, the motorcyle radio has the waterproof head, mic, and speaker.

I have a range 2 analog Spectra in a dashmount configuration (D34KXA7JA7AK), with a 30w PA. I bought it on ebay a few years ago, and I think it came from Canada.

[ASTROMODAT]

I think you are correct that in Canada there was a 430 - 470 Spectra in dash mount. It's weird how they have these subtle differences between markets. I can understand 430- 470 for the off-shore markets, as they have commercial frequencies in the 430 - 440 band, such as in Israel, which is a boon to Hams in buying used Motorola's.

[Josh]

Yeah, I am going to do a conversion from a UHF 403-433 Astro 110watt W9 to an 800Mhz 15watt analog spectra.

I've got the Astro manuals, so in order to do the RF board work, all I have to do is compare the schematic for the 800Mhz RF board with the UHF board I'll possess and work that up -or- do I do work on the 800Mhz analog RF board and upgrade it to match the schematic in the book?

Not too sure from the wording of the first post.

-Josh

[motorola_otaku]

Nah, you need to use the Astro RF board as a starting point. The analog board isn't capable of processing digital.

[Josh]

Alright, yeah, makes more sense that way lol.

I see what I might need to do, but I have to get the radio in my hands first to see if the RF board is the version of the HRN6020 (A B or C unsure on the difference) that can be direclty compared to the 800/vhf RF boards in terms of parts.

It should be here before Christmas, I'm kinda excited about it- then I'll have use for this 110 watt spectra mounting bracket aside from aiding in the aeration of my laptop computer by using it as a convenient computer stand.

-Josh

[boem2134]

Hello everyone I need to convert a VHF spectra to a spectra, I know I need a RF, Command and a VoCoder, is there anything else, and where can I find the part numbers for these, along with the part number for the 2.5K rf board if I could find one.

Thanks


Bob

[jmr061]

Finding a 2.5 khz RF board is going to be VERY hard. A new one is like 800 bucks. Your best bet is either search for a used 2.5 khz radio or build a non 2.5 khz radio as the those boards are not to hard to find.

Jason

[tvsjr]

Hello everyone I need to convert a VHF spectra to a spectra, I know I need a RF, Command and a VoCoder, is there anything else, and where can I find the part numbers for these, along with the part number for the 2.5K rf board if I could find one.

Thanks


Bob

HRN6014K is the 2.5-ready 146-174 RF deck. I've got one sitting here in front of me. They're about $570 dealer cost. And quite rare to find on the used market.

[jmr061]

Actually the rf boards cover either the entire vhf, uhf or 800 range. In other words the vhf rf board covers both band splits in vhf, the uhf rf board covers ALL band splits in UHF 403-512.

Jason

[motorola_otaku]

Hello everyone I need to convert a VHF spectra to a spectra, I know I need a RF, Command and a VoCoder, is there anything else, and where can I find the part numbers for these, along with the part number for the 2.5K rf board if I could find one.

Thanks


Bob

HRN6014K is the 2.5-ready 146-174 RF deck. I've got one sitting here in front of me. They're about $570 dealer cost. And quite rare to find on the used market.

And on top of that, the radio's firmware needs to be told that it's capable of 2.5 kHz-spaced frequencies. Obviously, this is a factory-only procedure.

KST, do you know for a fact that the new 2.5 kHz VHF boards cover the entire 136-174 range?

[jmr061]

Yes they cover the entire range. In order to support the 2.5 board the vocon must be 1 meg with 9.51.00 or later host.

Jason

Hello everyone I need to convert a VHF spectra to a spectra, I know I need a RF, Command and a VoCoder, is there anything else, and where can I find the part numbers for these, along with the part number for the 2.5K rf board if I could find one.

Thanks


Bob

HRN6014K is the 2.5-ready 146-174 RF deck. I've got one sitting here in front of me. They're about $570 dealer cost. And quite rare to find on the used market.

And on top of that, the radio's firmware needs to be told that it's capable of 2.5 kHz-spaced frequencies. Obviously, this is a factory-only procedure.

KST, do you know for a fact that the new 2.5 kHz VHF boards cover the entire 136-174 range?

[motorola_otaku]

Yes they cover the entire range. In order to support the 2.5 board the vocon must be 1 meg with 9.51.00 or later host.

Cool deal. But let's say I get a 2.5 kHz board and drop in my radio with the appropriate HOST revision.. won't the software still throw errors at me for being unable to handle 2.5 kHz spaced frequencies and refuse to write to the radio?

[jmr061]

The radio and cps/rss communicate with each other and the radio either rejects or accepts the 2.5 khz spaced frequencies depending on the radio's hardware configuration. If its properly hardware equipped for 2.5 khz channels it will take them, if not you get a rejection notice when trying to program it.

A 2.5khz VHF RF board is part #HRK6014C or later revsion.

Jason

[ka8ypy]

Send a PM to SGLASS for an Astro VHF RF Board.

I think he has a few.

DB

[motorola_otaku]

On a related note, I just acquired a 110-watt Q-split Astro Spectra. Instructions for converting the high-power PA deck from 403-433 to 450-482 may be forthcoming over the next week or so, assuming I don't get lazy and just drop it in the 45w chassis I already have.

[motorola_otaku]

Okay, so my shiny new detailed Spectra service manual covers everything EXCEPT the 110-watt PA decks. Anyone feel like snapping me some hi-res pics of a Range 3 (450-482) high-power PA deck?

[motorola_otaku]

Or, close to a year later, I could do it myself.





First picture is of a Range 1 403-433 110-watt PA board. Second is of a Range 3 450-482 board. You'll notice that there are a couple of ceramic jumpers moved around between boards, as well as the removal of a 100-ohm resistor and a lengthened coil. These are the ONLY differences between the two boards. Everything else is 100% identical. However, for some Godforsaken reason, I moved the jumpers, put in a 6-turn coil, and pulled the 100-ohm resistor, and the damn thing still wouldn't do full power above 438 MHz. I dunno.

[RFguy]

I would suspect that there will also be some component value changes. Slightly different capacitor values for example

[bellersley]

...which the service manual explains in detail.

[motorola_otaku]

...which the service manual explains in detail.

Well, at the time I didn't have one.

Riddle me this: is there a UHF range 2 110-watt PA board documented in the detailed service manual?

[jmr061]

No there was not a range 2 uhf 110 watt board made. Rumor is they had a 45 watt range 2 uhf radio but I have never seen it documented. Highest I have seen is a 25 watt. I do use a 110 watt range 3 PA board for my range 2 radio and it works fine.

Jason

[ka8ypy]

The PA section should work for all ranges...The issue is the RF board, it needs to be modified to come up from range 1 to range 2. BTW an RF board out of a low/mid power spectra will work in a high power spectra.

Guess it's time to stare and compare components on the RF boards...

The board numbers are the same 6014, but the ranges are different as noted by the letter at the end A, B, C and D. These are not revision letters but range letters. And the detailed manual does not cover the "B" rf board.

Does anyone have a detailed maintanace manual for a Astro Motorcycle radio??

There is, however information on components for the UHF Range 2 VCO Hybrid in the detailed maintenance manual. (Page 7-95 for the pics and 7-96 for parts list)

[jmr061]

Wow where did you get the info that the RF board is range specific. It IS the same for ALL UHF ranges. Otherwise I would have a bunch of radios that would not be working when they are.

Jason

[ka8ypy]

Wow where did you get the info that the RF board is range specific. It IS the same for ALL UHF ranges. Otherwise I would have a bunch of radios that would not be working when they are.

Jason

Guess I mis read the schematic in the detailed maintenance manual...shows different values on the various boards (A, C, and D) so figured they were for the diffent ranges.

Oh well, chalk one up for flawed logic.

[TWEMARS]

At this point I realize that this topic is ancient history but I did a couple of these a few years ago.

UHF: I got a $39 donor 420 radio from fleBay and removed the receiver synthesizer (same for 403-433 and 450-470, vocoder and audio board. I then installed these into my old analog Spectra, put in a new motorcycle S record to get 438-470 operation, tuned the radio and went to town.

VHF: I also did a VHF but I used all the receiver synthesizer and audio board from a 100 watt Astros that I got for like $70 for a pile of 5 then provided my own vocoder and did pretty much the same as above.

Note that I did W7's so I was able to use Motorcycle radio S records and get 438-470 operation without any RSS hacks...If there was a W9 motorcycle radio this would also work.

I don't know about Astros but Analog Spectras are too dumb to know whether the radio power level matches the codeplug or not. 100 watt codeplug bashed into a 40 watt radio works just fine and no need to maintain multiple codeplugs for multiple radio power levels.

Final note: I ran the control head to radio cable to a 25 pin 4 way DB25 printer switch, added two more radios (an 800 and a 420) and made my own poor man's multiple radio.

[motorola_otaku]

FYI if you upgrade firmware to R11.71.07/N08.03.05 you can TX P25 below 450 MHz in a Range 3 UHF radio without having to force in a motorcycle radio S-record. I've done several and they all work great.