RE: [Repeater-Builder] Micor power supply replacement series regulator transistor
The M9698 pass transistor seems to have been used only in the TPN1151A power supply, which was used in relatively few Micor stations. Once I figured out what power supply used that transistor, I found that its complete part number is 4800869698. It is still available from Motorola Parts for about $20 each. However, the Motorola catalog states that it is the same as the 2N5302 commercial part. The Mouser catalog lists the 2N5302G for just over three bucks a pop. The "G" suffix means that the item is lead-free. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of wa5luy Sent: Thursday, December 25, 2008 4:42 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor power supply replacement series regulator transistor Does anyone have a replacement number for the Motorola M9698 regulator transistors used in the Micor power supply? I am looking for a house number I can order from Mouser. Our trusted repeater of many years let the smoke out Christmas Eve. Guess Santa got too close to the tower. 73 WA5LUY
[Repeater-Builder] Micor power supply replacement series regulator transistor
Does anyone have a replacement number for the Motorola M9698 regulator transistors used in the Micor power supply. I am looking for a house number I can order from Mouser. Our trusted repeater of many years let the smoke out Christmas Eve. Guess Santa got to close to the tower. 73 WA5LUY
RE: [Repeater-Builder] Micor Power Supply or Astron Supply?
Robert, My vote is for the Motorola TPN1106. Besides having the appropriate regulators and cable harness, it is capable of operating continuously at full load, which the Astron RM-50 cannot do. The Motorola is marginally more efficient, 63% versus 59%. What is important is that the TPN1106 with the C29 Battery Protection and Alarm Kit includes on-air alarm tone and low-voltage disconnect, which the Astron lacks. I believe that the Micor TPN1106 represents the high-water mark in heavy-duty station power supply design, while the Astron is designed to meet a profit target and is a lightweight contender by comparison. Opinions vary... 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of georgiaskywarn Sent: Wednesday, October 22, 2008 5:12 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Power Supply or Astron Supply? What say the group; Micor TPN-1106 (w/battery backup) or Astron RM-50M (w/battery backup) Add on some sort of 9.6v reg. board for the Astron. Don't have a TPN-1106 yet but will be looking for one if I do go that route. PA is 100watt cont. Have a TPN-1100B right now. If there is a add on board for that (and have been told there is not)...might look at that. Will be making a quick run to the Stone Mtn Hamfest in ATL on Nov 1st if someone has one for sell. Thanks, Robert KD4YDC
[Repeater-Builder] Micor Power Supply or Astron Supply?
What say the group; Micor TPN-1106 (w/battery backup) or Astron RM-50M (w/battery backup) Add on some sort of 9.6v reg. board for the Astron. Don't have a TPN-1106 yet but will be looking for one if I do go that route. PA is 100watt cont. Have a TPN-1100B right now. If there is a add on board for that (and have been told there is not)...might look at that. Will be making a quick run to the Stone Mtn Hamfest in ATL on Nov 1st if someone has one for sell. Thanks, Robert KD4YDC
RE: [Repeater-Builder] Micor Power Supply
Ken, The information you seek is contained in the Power Supply Service Manual, publication 6881094E30, which is available from Motorola Parts for about $19. Call 800-422-4210 to place an order. This is an extremely valuable reference manual, and once the existing stock is depleted it probably will be NLA. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of wb6mmv Sent: Monday, August 11, 2008 8:06 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Power Supply I recently received a Micor repeater power supply from an SK and was wondering if there are any schematics available for it? The model number is TPN 1217B. Thanks Ken WB6MMV
[Repeater-Builder] Micor Power Supply
I recently received a Micor repeater power supply from an SK and was wondering if there are any schematics available for it? The model number is TPN 1217B. Thanks Ken WB6MMV
[Repeater-Builder] Micor power supply on ebay
Speaking of the devil: Motorola Micor Power Supply Ebay Item number: 140199498746 Don't delay... at the time of this posting there are only two hours left in the auction. You might look up the old auction number and ask the seller to relist it if it doesn't go the first time out. cheers, s.
Re: [Repeater-Builder] Micor power supply issue
While I don't have experience with that particular power supply, the situation you describe is symptomatic of filter capacitor failure. The capacitor's equivalent series resistance (ESR) becomes so high that it doesn't filter the ac ripple anymore. You should be able to verify this easily by using a scope to observe the ac ripple on the dc output under various load conditions. Eric KH6CQ --- kk2ed <[EMAIL PROTECTED]> wrote: > Good Evening, > > I have a Micor 75 station power supply that is > acting up. When the > repeater is idle, the voltage output appears clean. > But as the load > is increased (ie: power output increased), the > voltage sags and I > get an annoying hum on the tx (indicative of AC > ripple on the dc > side?). It started out as a barely noticeable hum; > the past few > days it has gotten to the point where I just shut > down the > repeater's tx. > > I haven't had a chance to get to the site to swap it > out with a > spare. But I'm curious as to what kind of repair I'm > in for, and > others' experience with Micor supplies. > > What tends to be the failure and/or cause of the > above condition? > > Pass transistor failure? Filter caps? Ferro-resonant > circuit (cap)? > > Thanks for any input > Eric > KE2D > > > Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
RE: [Repeater-Builder] Micor power supply issue
Eric, Without knowing what model of power supply you have, my first guess is that you have an open diode in the high-current supply. An open diode will cause low voltage, high ripple, and major hum. However, your comment suggests a gradual onset of hum, which may indicate a filter capacitor failure. If your power supply has a ferro-resonant transformer, you may have a bad commutating capacitor. Not enough info to make this call... Do you have the manual for your specific power supply? If not, what model power supply is it? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of kk2ed Sent: Thursday, January 17, 2008 7:59 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor power supply issue Good Evening, I have a Micor 75 station power supply that is acting up. When the repeater is idle, the voltage output appears clean. But as the load is increased (ie: power output increased), the voltage sags and I get an annoying hum on the tx (indicative of AC ripple on the dc side?). It started out as a barely noticeable hum; the past few days it has gotten to the point where I just shut down the repeater's tx. I haven't had a chance to get to the site to swap it out with a spare. But I'm curious as to what kind of repair I'm in for, and others' experience with Micor supplies. What tends to be the failure and/or cause of the above condition? Pass transistor failure? Filter caps? Ferro-resonant circuit (cap)? Thanks for any input Eric KE2D
Re: [Repeater-Builder] Micor power supply issue
The main supply is only used for the PA, so a bit of AC there won't cause hum in the audio. Check the regulated 9.6 and 12.v supplies on the PC board, these tend to dry out the 100uf caps causing hum. A simple check with a scope will tell all. Motorola's spec on AC is 60millivolts, max. on any supply. if your main supply is sagging below 13.0 volts, check the 2 chassis mounted diodes. it is normal for this part of the supply to start out at about 15.5 volts and drop to as low as 13 ( normal). lance N2HBA - Original Message - From: kk2ed To: Repeater-Builder@yahoogroups.com Sent: Thursday, January 17, 2008 10:59 PM Subject: [Repeater-Builder] Micor power supply issue Good Evening, I have a Micor 75 station power supply that is acting up. When the repeater is idle, the voltage output appears clean. But as the load is increased (ie: power output increased), the voltage sags and I get an annoying hum on the tx (indicative of AC ripple on the dc side?). It started out as a barely noticeable hum; the past few days it has gotten to the point where I just shut down the repeater's tx. I haven't had a chance to get to the site to swap it out with a spare. But I'm curious as to what kind of repair I'm in for, and others' experience with Micor supplies. What tends to be the failure and/or cause of the above condition? Pass transistor failure? Filter caps? Ferro-resonant circuit (cap)? Thanks for any input Eric KE2D
[Repeater-Builder] Micor power supply issue
Good Evening, I have a Micor 75 station power supply that is acting up. When the repeater is idle, the voltage output appears clean. But as the load is increased (ie: power output increased), the voltage sags and I get an annoying hum on the tx (indicative of AC ripple on the dc side?). It started out as a barely noticeable hum; the past few days it has gotten to the point where I just shut down the repeater's tx. I haven't had a chance to get to the site to swap it out with a spare. But I'm curious as to what kind of repair I'm in for, and others' experience with Micor supplies. What tends to be the failure and/or cause of the above condition? Pass transistor failure? Filter caps? Ferro-resonant circuit (cap)? Thanks for any input Eric KE2D
RE: [Repeater-Builder] Micor power supply voltage sag
Eric, I ran some load tests on a number of Motorola, GE, Astron, and Samlex power supplies, including the TPN1110. When connected to a suitably "stiff" 120 VAC power source, the TPN1110 is specified to deliver a quasi-regulated output for the PA of 13.8 VDC at 25 amperes. I use the term quasi-regulated because the TPN1110 uses a ferro-resonant power transformer at the AC input side, but the high-current output is not regulated. Here is an excerpt of my load test on a new-in-box TPN1110B: 15.74 VDC at no load 15.06 VDC at 5.0 amps load 14.71 VDC at 10.0 amps load 14.37 VDC at 15.0 amps load 14.04 VDC at 20.0 amps load 13.74 VDC at 25.0 amps load 13.39 VDC at 30.0 amps load 13.01 VDC at 35.0 amps load The test was performed with no loads on the other, regulated outputs of the power supply. My test bench has a dedicated 20-ampere circuit that varies very little under a heavy load. In fact, the AC input voltage to the TPN1110 supply was 121.7 VAC at no load and 120.2 VAC at 35.0 amps DC load. That's an extremely stiff power source. Most residential receptacle voltages are much less stiff, for a number of reasons, and may contribute to less than satisfactory operation. Try using a true-RMS digital multimeter to measure the AC input voltage of your power supply when it is under load. If it falls below 110 volts, the ferro-resonant transformer may be unable to compensate for the undervoltage condition. The national standard for nominal receptacle voltage is 120 +/- 6 VAC. You must use a true-RMS meter to read the input voltage, because its input current is not a pure sine wave, and a conventional meter will not read accurately. The +9.6 VDC output of the TPN1110B power supply uses the same full-wave rectifier as the high-current output. It the 9.6 VDC output has a high ripple content, one of the diodes in the full-wave rectifier may be open. You can also use a scope to view the rectifier output to verify that conduction occurs on each half cycle. If all of this checks out, the compensating capacitor at the transformer may be bad. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of kk2ed Sent: Friday, September 07, 2007 11:16 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor power supply voltage sag Good Afternoon, While going thru my Micor stuff, I found that one of my station power supplies (TRN1011?) suffers from voltage sag under load. I know that by design the power supply voltage should drop under load. Most will idle around 15v, then drop to about 13v under load of a 100w PA. But this unit is sagging to almost 11v under heavy loads, thus resulting in the PA output being lower than normal. Anyone have this issue before and know what the cause might be? One of the two pass/regulator transistors bad? Transformer on the way out? Or bad cap? Suggestions appreciated before I tear into it. Eric KE2D
Re: [Repeater-Builder] Micor power supply voltage sag
If it's the TPN1110 supply, the PA supply is very simple. A ferro-resonant transformer, two diodes, and LOTS of capacitors. The transistors are for the low-current regulated supply. One diode could be open. If so, I'd expect a lot of ripple on the supply and low voltage. If one cap was bad, I doubt you'd even notice it. The PA could also be drawing a lot more than the 25 amps the supply is rated for, thus giving you less voltage to feed it. Your wattmeter or load could be in error, thus forcing the above condition. Bob M. == --- kk2ed <[EMAIL PROTECTED]> wrote: > Good Afternoon, > > While going thru my Micor stuff, I found that one of > my station power > supplies (TRN1011?) suffers from voltage sag under > load. I know that > by design the power supply voltage should drop under > load. Most will > idle around 15v, then drop to about 13v under load > of a 100w PA. But > this unit is sagging to almost 11v under heavy > loads, thus resulting > in the PA output being lower than normal. Anyone > have this issue > before and know what the cause might be? One of > the two > pass/regulator transistors bad? Transformer on the > way out? Or bad > cap? Suggestions appreciated before I tear into it. > > Eric > KE2D Luggage? GPS? Comic books? Check out fitting gifts for grads at Yahoo! Search http://search.yahoo.com/search?fr=oni_on_mail&p=graduation+gifts&cs=bz
[Repeater-Builder] Micor power supply voltage sag
Good Afternoon, While going thru my Micor stuff, I found that one of my station power supplies (TRN1011?) suffers from voltage sag under load. I know that by design the power supply voltage should drop under load. Most will idle around 15v, then drop to about 13v under load of a 100w PA. But this unit is sagging to almost 11v under heavy loads, thus resulting in the PA output being lower than normal. Anyone have this issue before and know what the cause might be? One of the two pass/regulator transistors bad? Transformer on the way out? Or bad cap? Suggestions appreciated before I tear into it. Eric KE2D
Re: [Repeater-Builder] Micor power supply rating, how many amps does it produce
Most of the supplies are rated for 14-15V at around 35 amps. This would typically be for a 110w station. A model number would probably help get you an official rating however. Bob M. == --- n9lv <[EMAIL PROTECTED]> wrote: > Is there a way to find out how many amps a power > supply is from a > motorola micor system. For instance a power supply > from a 100 watt > system? A way to look up the model numbers. I am > trying to develope a > power supply capable of giving at least 40 amps > continous duty that is > rack mountable. Currently I have an Astron 70 amp > power supply, but > would like to remove that amp and replace it with > something that is > rack mountable, but don't want to incur the cost of > buying a new one if > the two that I have will work. > > Mathew __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
[Repeater-Builder] Micor power supply rating, how many amps does it produce
Is there a way to find out how many amps a power supply is from a motorola micor system. For instance a power supply from a 100 watt system? A way to look up the model numbers. I am trying to develope a power supply capable of giving at least 40 amps continous duty that is rack mountable. Currently I have an Astron 70 amp power supply, but would like to remove that amp and replace it with something that is rack mountable, but don't want to incur the cost of buying a new one if the two that I have will work. Mathew
[Repeater-Builder] micor power supply
I have a TPN1121A it has not input cord so I am not sure if it hooks up to a 120 volt line or what can anyone help me with specs on this power supply. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Micor Power Supply
Any one know where I can pick off 9.6 vdc on the TLN5123B supply? Thanks. Lloyd KD4HTW Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Micor Power Supply with Battery Charger
Reading from the Motorola Micor "Compa Station" manual having to do with this power supply: for TPN1105A and TPN1106A ... manual part number 68P81104E92 TPN1105A 121 or 242 V RMS 50 or 60 Hz TPN1106A 121 V RMS 60 Hz Factory Installed Optional Accessories: C28 c/o TPN1106A, with Battery Charger C38 c/o TPN1105A, with Battery Charger C29 c/o C28 or C38 and the Battery Protection and Alarm Description: The C28, C38 and C29 options are factory installed accessories that are available for all models of Motorola "Micor" base and repeater stations, either locally or remotely controlled. * The C28 option permits the station to oper- ate from 121 volt, 60 Hz ac power normally, but provides continued operation from 12-volt bat- teries (emergency power) if the ac power should fail. When ac power is restored, the power supply also operates as a battery charger to re- charge the batteries. * The C38 option is the same as the C28 op- tion except that it operates from 121 or 242 volt, 50 or 60 Hz ac power, as well as 12 volt batteries. * The C29 option is available only if the C28 or C38 power supply/battery charger option is also included. The C29 option is a Battery Pro- tection & Alarm package that can be factory installed, to improve emergency power backup by providing an audible alarm whenever the station is operating on batteries. The battery protection and alarm option generates an audible alarm tone which "beeps" to indicate that the station is oper- ating on emergency power. This tone burst, with a frequency of about 1400 Hz, is approximately 1/4 second long and repeats at 2 1/2 second inter- vals. On remote control stations, or repeater station with wire line control, the alarm tone is injected into the audio line and is heard at the console (except when transmitting). On repeater stations, without wire line control, the tone is transmitted whenever the transmitter is keyed, so that anyone receiving signals from this station will know that it is operating on emergency power. (The description continues ...) As I remember, the output voltage (battery charging voltage) control is behind two chassis panels and one circuit board. All must be removed prior to making the voltage adjustment. (Be careful) The fix for this is to drill holes in those chassis panels and the circuit board before installing the power supply ... and then use an insulated tool to make the adjustment. The only relay involved with these power supplies is the discharged battery disconnect relay that comes with the C29 option. Hope this helps, Neil McKie - WA6KLA Eric Lemmon wrote: > > Kelly, > > It would have been nice, had you included those seven numbers in > your posting. But, by your description, I think you have either > the TPN1105A or TPN1106A power supply. The model number is usually > stamped on a box that is immediately below the large black > transformer. The TPN1105A operates only on 120 VAC 60 Hz, while > the TPN1106A can operate on either 120 VAC or 240 VAC, and 50 or 60 > Hz. I believe that you have one of these units, because your > description of a "squeal" as it starts tells me that it incorporates > a switching power supply circuit. Earlier units were linear in > design, and made no such noise. > > Either of the above units may be equipped with Option C29, called > the Battery Protection & Alarm option. This provides a relay closure > when AC power fails, and it also injects a periodic beep into the > audio to alert the users that it is on battery power. The C29 option > also can lower the PA power when on batteries, and shut down the > repeater when the battery voltage falls below a safe level. > > These power supplies can be adjusted, with an internal pot, to float > nicad batteries at 14.25 VDC or lead-acid batteries at 13.0 VDC. > Before connecting your power supply to any batteries, you should > check and/or adjust the voltage to the proper level using an accurate > DVM. Most MICOR stations installed with battery backup used Motorola > nicad batteries rather than lead-acid, so don't assume that the > voltage is set for the latter. > > Obtain Motorola publication 6881104E92 for operation and service > information. > > 73, Eric Lemmon WB6FLY > > [EMAIL PROTECTED] wrote: > > > > I have acquired a couple of the Micor Power Supplies with the > > Battery Charger. Now I asked the local Motorola shop about > > purchasing a service manual. They are more than happy to help, > > but need the typical xxxz part number. Well, there are 7 such > > numbers stamped on various places of the unit. These are probably > > subassembly part numbers. > > > > Let me describe the thing and no doubt some of you will recognize > > it. It is heavier than other Micor power supplies, has a larger > > heat sink, and squeaks when powered up. There is a
Re: [Repeater-Builder] Micor Power Supply with Battery Charger
That is about 2/3rds of the schematic diagram. Neil - WA6KLA Adi Linden wrote: > > > Let me describe the thing and no doubt some of you will recognize > > it. It is heavier than other Micor power supplies, has a larger > > heat sink, and squeaks when powered up. There is apparently an > > audio signal and PTT(can I use that acronym anymore) to indicate > > battery mode, and a low voltage shutoff adjustment. I'd really > > like to make use of these features. Do any of you recognize it? If > > you do I need to order a service manual for this model. If you > > happen to have a manual that could be parted with, please let me > > know. > > I am not very familiar with Motorola power supplies, but I have one > that matches your description, it has TPN1106 stamped on its side. > There is a schematic at > http://www.repeater-builder.com/pix/micor-ps-tpn-1106.jpg > > Adi > -- >Adi Linden | va3adi | [EMAIL PROTECTED] | http://adis.ca > +-+ > IRLP Node 2590 in Sioux Lookout, Ontario > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Micor Power Supply with Battery Charger
Kelly, It would have been nice, had you included those seven numbers in your posting. But, by your description, I think you have either the TPN1105A or TPN1106A power supply. The model number is usually stamped on a box that is immediately below the large black transformer. The TPN1105A operates only on 120 VAC 60 Hz, while the TPN1106A can operate on either 120 VAC or 240 VAC, and 50 or 60 Hz. I believe that you have one of these units, because your description of a "squeal" as it starts tells me that it incorporates a switching power supply circuit. Earlier units were linear in design, and made no such noise. Either of the above units may be equipped with Option C29, called the Battery Protection & Alarm option. This provides a relay closure when AC power fails, and it also injects a periodic beep into the audio to alert the users that it is on battery power. The C29 option also can lower the PA power when on batteries, and shut down the repeater when the battery voltage falls below a safe level. These power supplies can be adjusted, with an internal pot, to float nicad batteries at 14.25 VDC or lead-acid batteries at 13.0 VDC. Before connecting your power supply to any batteries, you should check and/or adjust the voltage to the proper level using an accurate DVM. Most MICOR stations installed with battery backup used Motorola nicad batteries rather than lead-acid, so don't assume that the voltage is set for the latter. Obtain Motorola publication 6881104E92 for operation and service information. 73, Eric Lemmon WB6FLY [EMAIL PROTECTED] wrote: > > I have acquired a couple of the Micor Power Supplies with the Battery > Charger. Now I asked the local Motorola shop about purchasing a service > manual. They > are more than happy to help, but need the typical xxxz part number. Well, > there are 7 such numbers stamped on various places of the unit. These are > probably subassembly part numbers. > > Let me describe the thing and no doubt some of you will recognize it. It is > heavier than other Micor power supplies, has a larger heat sink, and squeaks > when powered up. There is apparently an audio signal and PTT(can I use that > acronym anymore) to indicate battery mode, and a low voltage shutoff > adjustment. > I'd really like to make use of these features. Do any of you recognize it? If > you do I need to order a service manual for this model. If you happen to have > a > manual that could be parted with, please let me know. > > Kelly Fowler, KE4ADV > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Micor Power Supply with Battery Charger
> Let me describe the thing and no doubt some of you will recognize it. It is > heavier than other Micor power supplies, has a larger heat sink, and squeaks > when powered up. There is apparently an audio signal and PTT(can I use that > acronym anymore) to indicate battery mode, and a low voltage shutoff > adjustment. > I'd really like to make use of these features. Do any of you recognize it? If > you do I need to order a service manual for this model. If you happen to have > a > manual that could be parted with, please let me know. I am not very familiar with Motorola power supplies, but I have one that matches your description, it has TPN1106 stamped on its side. There is a schematic at http://www.repeater-builder.com/pix/micor-ps-tpn-1106.jpg Adi -- Adi Linden | va3adi | [EMAIL PROTECTED] | http://adis.ca +-+ IRLP Node 2590 in Sioux Lookout, Ontario Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
[Repeater-Builder] Micor Power Supply with Battery Charger
I have acquired a couple of the Micor Power Supplies with the Battery Charger. Now I asked the local Motorola shop about purchasing a service manual. They are more than happy to help, but need the typical xxxz part number. Well, there are 7 such numbers stamped on various places of the unit. These are probably subassembly part numbers. Let me describe the thing and no doubt some of you will recognize it. It is heavier than other Micor power supplies, has a larger heat sink, and squeaks when powered up. There is apparently an audio signal and PTT(can I use that acronym anymore) to indicate battery mode, and a low voltage shutoff adjustment. I'd really like to make use of these features. Do any of you recognize it? If you do I need to order a service manual for this model. If you happen to have a manual that could be parted with, please let me know. Kelly Fowler, KE4ADV Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
