From scr287 at att.net Wed Jun 3 16:21:08 2015 From: scr287 at att.net (Jack Antonio) Date: Wed, 03 Jun 2015 16:21:08 -0400 Subject: [Motorola] P23AAM Help needed Message-ID: <556F61B4.2070002@att.net> So, I'm working on bringing a pair of H23AAMs back to life. And they appear to have power supply troubles. They have the NU-137-3 Nicad supply. I have the book for the Low Band radio, with the NU-137 and here is the problem, the two aren't not agreeing with each other. So a couple of questions. What is an MN24 transistor? NPN or PNP? The book shows PNP, the parts list says type XN12. Anyone have a later schematic than the 1956 version I have? The H/P23BAC book on the repeater-builders website shows a completely different power supply. Thanks Jack Antonio WA7DIA/4 From Geoff at wb6nvh.com Wed Jun 3 18:18:55 2015 From: Geoff at wb6nvh.com (Geoff Fors) Date: Wed, 3 Jun 2015 15:18:55 -0700 Subject: [Motorola] P23AAM Help needed References: <556F61B4.2070002@att.net> Message-ID: <164E6B5761684D11BF434190CDF1234D@dell549557a818> Jack, I will look through my library when I get home and see what I have. The AAM series portable uses a different receiver than the BAM. The BAM has an all solid state receiver while the AAM uses two subminiature wire-lead tubes in the IF stage. As a result, the power supplies are completely different and as I recall, the wiring harnesses and the connectors are as well. All transistors should be PNP Germanium. At that time that was the standard. Because of the differences, a BAM manual will be more or less hopeless as far as helping you with the earlier AAM series. The audio section PC boards on these usually have a few tantalum slug capacitors that by now have eaten their leads off or are growing flowers out the ends, or both. Most of the tubular electrolytics are probably dried up throughout the set and a quick trip through it with an ESR meter will find which ones have. I have found on my BAM's that five D style NiCads in a plastic holder for six will fit where the original NiCad battery went. You have to short across the empty cell holder on a six battery setup. For some reason if you try to use six batteries the receiver becomes unstable above 7V and goes into oscillation and/or other strange behavior. To further muddy the water, in 1962-64 Motorola started selling field retrofit kits to convert the AAM series radios into BAM series with solid state receivers, through conversion kits. Among other things the kits included a new receiver board and some power supply modification kits, and those had a sticker which looked like the symbol for a transistor that you applied to the side of the radio. I saw some depot overhauled and upgraded radios that had the transistor symbol screened in paint on the sides. Note that the power supply is a DC-DC converter that runs all the time and powers the receiver as well as the transmitter, so that even though the set is technically positive ground, it is being powered by the secondary of the power transformer and thus unrelated to the vehicle ground when you use the 12 Volt adapter cable that plugs in where that little door is. A 1956 manual would be the first one as the radio wasn't even introduced to the market until 1957. For various reasons the AAM series are always in need of a lot of work when I get them, while the BAM's seem to always fire right up as they are. By the way, the cost of crystals today is outrageous. Typically $ 25 - 35 each. Geoff WB6NVH Monterey CA From tbryan at nova.org Wed Jun 3 18:25:07 2015 From: tbryan at nova.org (Tom B) Date: Wed, 03 Jun 2015 18:25:07 -0400 Subject: [Motorola] P23AAM Help needed In-Reply-To: <556F61B4.2070002@att.net> References: <556F61B4.2070002@att.net> Message-ID: <556F7EC3.1070506@nova.org> Hi Jack, Glad to hear the someone else is interested in this old stuff. The MN24 is a PNP. I only have the H23-1 manual handy but it has the same part numbered transistor as your manual. The schematic show PNP. This website gives the specs for the MN24 as: http://alltransistors.com/transistor.php?transistor=41540 MN24 Transistor Datasheet. Parameters and Characteristics. Type Designator: MN24 Material of transistor: Ge Polarity: PNP Maximum collector power dissipation (Pc), W: 45 Maximum collector-base voltage |Ucb|, V: 40 Maximum collector-emitter voltage |Uce|, V: 0 Maximum emitter-base voltage |Ueb|, V: 0 Maximum collector current |Ic max|, A: 3 Maksimalna temperatura (Tj), ?C: 85 Transition frequency (ft), MHz: 0.3 Collector capacitance (Cc), pF: Forward current transfer ratio (hFE), min: 20 Noise Figure, dB: - Package of MN24 transistor: TO3 MN24 Equivalent Transistors - Cross-Reference Search Tom Bryan N3AJA On 6/3/2015 4:21 PM, Jack Antonio wrote: > So, I'm working on bringing a pair of H23AAMs back to life. > > And they appear to have power supply troubles. > > They have the NU-137-3 Nicad supply. I have the > book for the Low Band radio, with the NU-137 and > here is the problem, the two aren't not agreeing with > each other. > > So a couple of questions. > > What is an MN24 transistor? NPN or PNP? > The book shows PNP, the parts list says type XN12. > > Anyone have a later schematic than the 1956 version > I have? > > The H/P23BAC book on the repeater-builders website shows > a completely different power supply. From Geoff at wb6nvh.com Wed Jun 3 19:01:17 2015 From: Geoff at wb6nvh.com (Geoff Fors) Date: Wed, 3 Jun 2015 16:01:17 -0700 Subject: [Motorola] P23AAM Help needed References: <556F61B4.2070002@att.net> Message-ID: I checked and the schematic I have for the NU137 is dated 12-56, which I suspect is the same as your copy. That being said, the Motorola FM Schematic Digest by S. Wolf, the red edition, at Page 79 does show a set of NU-137 schematics dated 1958. I have not compared them with the '56 schematics to see what if anything is different. Do you have that book? The transistor crosses to an NTE 104, which is a Ge PNP TO-3 cased type with an Hfe of 90. The originals were probably far less than that. I would think that almost any Ge PNP TO-3 transistor, like that in an old car radio audio stage, would work. There may have been some service bulletins on these over the years which resulted in modifications. There was also a Z23AAC, which had a fully transistorized receiver, which would later become the H23BAC. Apparently it was never made with the NiCad supply, unlike the H23BAC. Geoff WB6NVH Monterey CA From scr287 at att.net Wed Jun 3 21:34:02 2015 From: scr287 at att.net (Jack Antonio) Date: Wed, 03 Jun 2015 21:34:02 -0400 Subject: [Motorola] P23AAM Help needed In-Reply-To: <164E6B5761684D11BF434190CDF1234D@dell549557a818> References: <556F61B4.2070002@att.net> <164E6B5761684D11BF434190CDF1234D@dell549557a818> Message-ID: <556FAB0A.8030301@att.net> Tom and Geoff Thanks for the information on the transistors and possible replacements. The NU-137 schematic I have is from an H21 manual, dated 3/56. The supplies on the H23AAMs are NU-137-3, and the date stamped inside radio is Dec. 1959. The radios themselves show the newer Motorola NLD-xxxx style numbers, but the supplies are from the older numbering system. The problem with the schematic I have is with the connector for the external cable, it appears the pin numbers have been transposed. As drawn, I don't see how the supply would have worked. I ohmmed it out and figured out some of it, but there are still some differences in the base biasing networks between the schematic and the supply itself. On the Z radios, I also have an AN/PRC-59, which looks like an H23BAC with a Coast Guard nameplate. Haven't done anything with it as yet. Thanks Jack From tbryan at nova.org Wed Jun 3 22:21:28 2015 From: tbryan at nova.org (Tom B) Date: Wed, 03 Jun 2015 22:21:28 -0400 Subject: [Motorola] P23AAM Help needed In-Reply-To: <556FAB0A.8030301@att.net> References: <556F61B4.2070002@att.net> <164E6B5761684D11BF434190CDF1234D@dell549557a818> <556FAB0A.8030301@att.net> Message-ID: <556FB628.7010707@nova.org> Hi Jack, The wiring for the dry cell pack on the A and B versions are wired differently. The schematic I have for the A version is dated 12/56. The B version manual I have is dated 11/61. I am not sure when they switched from the old numbering system to the new. The A version schematic shows that external power is connected to the 4 pin Jones plug. For 12V operation, pins 1 and 3 are connected together and pin 4 is negative and pin 2 is positive. The chassis is positive ground. Tom On 6/3/2015 9:34 PM, Jack Antonio wrote: > Tom and Geoff > > Thanks for the information on the transistors and possible > replacements. > > The NU-137 schematic I have is from an H21 manual, dated > 3/56. The supplies on the H23AAMs are NU-137-3, and > the date stamped inside radio is Dec. 1959. The radios > themselves show the newer Motorola NLD-xxxx style numbers, but > the supplies are from the older numbering system. > > The problem with the schematic I have is with the > connector for the external cable, it appears the > pin numbers have been transposed. As drawn, I don't > see how the supply would have worked. I ohmmed it out > and figured out some of it, but there are still > some differences in the base biasing networks between > the schematic and the supply itself. > > On the Z radios, I also have an AN/PRC-59, which looks > like an H23BAC with a Coast Guard nameplate. Haven't done > anything with it as yet. > > Thanks > > Jack From scr287 at att.net Fri Jun 19 12:22:18 2015 From: scr287 at att.net (Jack Antonio) Date: Fri, 19 Jun 2015 12:22:18 -0400 Subject: [Motorola] Systems 90 Message-ID: <558441BA.4000304@att.net> Hi all, I'm working toward bringing my old 8F 2Meter Micor back to life and have two requests. I found the radio, but the Systems 90 stack I had with it was no where to be found, so I'm trying to reconstruct it. The only thing I'm not redoing is the Touch-Code encoder. As I remember that thing was always a bit flaky. First, does anyone have an extra tan Systems 90 connector for a multiple PL encoder they could part with? A cut off would be fine as I only have a limited number of pins to stuff a bare shell with. Second. I have what appears to be an 8F channel scan card. The model number is faded, but I think it is TLN-9793A. It may be Canadian, as it appears that there might have been an M in front. Is there any documentation on it anywhere? All I have is the info for the 4 channel unit. Thanks in advance, Jack Antonio WA7DIA/4 From k0dan at comcast.net Thu Jun 25 21:43:52 2015 From: k0dan at comcast.net (K0DAN) Date: Thu, 25 Jun 2015 20:43:52 -0500 Subject: [Motorola] MOTOROLA SERVICE ANALYZER In-Reply-To: <5564A01F.8060205@att.net> References: <5564A01F.8060205@att.net> Message-ID: <93A0FE229F8848B78A7972F090BE5051@K0DANHamshack> I have an R2600B analyzer. It has the 10 Mhz spectrum analyzer but no tracking generator. It generally meets my needs, but a duplex sweep gen on the spectrum analyzer would be very handy. Does anyone know if the tracking generator can be added (hardware + software)? I realize the analyzer is no longer in production so this would be modification, add-on from dead unit, trade-up, etc. Alternatively, what would be a reasonable 4-sale value, and comparable trade-up to another model analyzer (Motorola, IFR, etc.)? I don't want to get into a lot of money, but want to explore my options. Thanks... dt From wb6fly at verizon.net Thu Jun 25 22:03:18 2015 From: wb6fly at verizon.net (Eric Lemmon) Date: Thu, 25 Jun 2015 19:03:18 -0700 Subject: [Motorola] MOTOROLA SERVICE ANALYZER In-Reply-To: <93A0FE229F8848B78A7972F090BE5051@K0DANHamshack> References: <5564A01F.8060205@att.net> <93A0FE229F8848B78A7972F090BE5051@K0DANHamshack> Message-ID: <003301d0afb4$45eae360$d1c0aa20$@verizon.net> The fellow who has the answers is Doyle Wofford, the service rep for Motorola / General Dynamics service monitors. If your R2600B is anything like my R2600D, most features are already inside the box, but simply need to be activated upon purchase of the upgrade key. Have the serial number of your unit in front of you when you call Doyle at 903-381-4156 or his cell phone 602-721-5889. 73, Eric Lemmon WB6FLY -----Original Message----- From: Motorola [mailto:motorola-bounces at mailman.qth.net] On Behalf Of K0DAN Sent: Thursday, June 25, 2015 6:44 PM To: Discussion of equipment manufactured by Motorola Subject: [Motorola] MOTOROLA SERVICE ANALYZER I have an R2600B analyzer. It has the 10 Mhz spectrum analyzer but no tracking generator. It generally meets my needs, but a duplex sweep gen on the spectrum analyzer would be very handy. Does anyone know if the tracking generator can be added (hardware + software)? I realize the analyzer is no longer in production so this would be modification, add-on from dead unit, trade-up, etc. Alternatively, what would be a reasonable 4-sale value, and comparable trade-up to another model analyzer (Motorola, IFR, etc.)? I don't want to get into a lot of money, but want to explore my options. Thanks... dt ______________________________________________________________ Motorola mailing list Home: http://mailman.qth.net/mailman/listinfo/motorola Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Motorola at mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html