Re: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750
rtc, Eric and Skipp, I remember one of the Kenwood repeaters I serviced few years back, the 720 I think. It was advertised as 50 watt repeater/base station. After looking at the final with only 1 transistor it had done as rtc stated; the PC board had gotten so hot it blackened/charred the PC board. After further study of the spec sheet found little beared? spec...for continous duty turn power down to 15 watts. Had to look hard. Always need to read the fine print. Also there was so much stuff in that unit to do the simple FM rx/tx functions. That is typical of Japan. 73, ron, n9ee/r From: rtc_0001 [EMAIL PROTECTED] Date: 2007/07/14 Sat PM 11:03:19 CDT To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750 It's not so much a defect as it is asking the rptr to do more than it was designed for. It may be a 45 watt PA but in rptr use, medium to HD rptr use, drop it down to about 25 to 30 watts out of the PA. Enjoy what you get thru the duplexer. Asking for more will melt the PA. The earlier units had a temp controlled fan that only came on when the PA was about to melt. The next generation of power supplies came with a switch to turn the fan on permanently. You will probably be able to fix them without the manual. Most of the time the PA transistor collector got hot, melted the solder the chip caps moved (slid down the pcb due to gravity). I repaired these on a regular basis without needing new parts unless the damage literaly burnt the pcb around the collector lead. I removed the chip caps, removed the solder on the collector tab trace resoldered it all back in with silver solder. This, along with turning the factory output down, made them last a long time even under HD casino use. I think it took me maybe 45-60 mins to get it all apart, fix it, reassemble, reinstall. Lots of times I did it in place at the customer's premises. rtc    -Original Message- From: Repeater-Builder@yahoogroups.com Sent: Friday, July 13, 2007 11:08 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750 Hi Eric, SNIP I just pulled three 1225 uhf repeaters from two different locations and they all have the same failed tx pa problems. Wonder if there's BR a minor pa defect problem (like there was in early version one tkr BR repeaters) or it's just bad customer karma time. I've got to find a service manual before we open them up... cheers, skipp Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
[Repeater-Builder] OFF Topic 2.4ghz
Does anyone know where or does anyone have any primestar dishes they would want to part with in and/or around the Indiana county area. I am wanting to make a 2.4 ghz reapeater hop. These are the old oval fiberglass dishes. The finances are low on this project. Thanks for the off topic entry. Denny ka3sxq
Re: [Repeater-Builder] Re: 224 MHz PA fun and war stories
Haven't tried it without a fan. I would guess that the giant heat sink on the original PA would probably handle the heat easily. My only concern would be the small contact area from each module; Would the heat dissipate properly? I have a PhD physicist business partner who could figure it out, but it's about as easy to add the fan. As K7IOU pointed out in the PA site, the fine print on that particular RF module says that the unit was not appropriate for repeater use due to the duty cycle. Not sure why they came to that conclusion. Of course, he read that AFTER the modules had been purchased. So, we went with them anyway. Almost two years later... go figure. de WD7F John in Tucson - Original Message - From: Nate Duehr [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Saturday, July 14, 2007 6:41 PM Subject: Re: [Repeater-Builder] Re: 224 MHz PA fun and war stories If a PA can't handle 48 hours of continuous key-down as-installed (fans if one must, etc.), it shouldn't be used on a repeater. You can find it on K7IOU's micor conversion page at http://home.comcast.net/~micorrepeater/220mhzpa.htm Thanks for sharing, John. It's on the must read pile! (GRIN) -- Nate Duehr, WY0X [EMAIL PROTECTED] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * 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] Re: Motorola R1225 versus Kenwood TKR-750
Most every mfgr is guilty of flashing the low duty cycle pa values with bold print but the commercial service lock to talk numbers seem to get lost in the small print. After the Motorola Service Manual arrives... I'll let you know what I/we find with the 1225 repeater pa. cheers, skipp rtc_0001 [EMAIL PROTECTED] wrote: It's not so much a defect as it is asking the rptr to do more than it was designed for. It may be a 45 watt PA but in rptr use, medium to HD rptr use, drop it down to about 25 to 30 watts out of the PA. Enjoy what you get thru the duplexer. Asking for more will melt the PA. The earlier units had a temp controlled fan that only came on when the PA was about to melt. The next generation of power supplies came with a switch to turn the fan on permanently. You will probably be able to fix them without the manual. Most of the time the PA transistor collector got hot, melted the solder the chip caps moved (slid down the pcb due to gravity). I repaired these on a regular basis without needing new parts unless the damage literaly burnt the pcb around the collector lead. I removed the chip caps, removed the solder on the collector tab trace resoldered it all back in with silver solder. This, along with turning the factory output down, made them last a long time even under HD casino use. I think it took me maybe 45-60 mins to get it all apart, fix it, reassemble, reinstall. Lots of times I did it in place at the customer's premises. rtc -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Friday, July 13, 2007 11:08 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750 Hi Eric, SNIP I just pulled three 1225 uhf repeaters from two different locations and they all have the same failed tx pa problems. Wonder if there's a minor pa defect problem (like there was in early version one tkr repeaters) or it's just bad customer karma time. I've got to find a service manual before we open them up... cheers, skipp
Re: [Repeater-Builder] OFF Topic 2.4ghz
Here in the Chicago area, one only has to drive a few blocks down any suburban side street and you'll find one, just sitting idle on a roof or deck, free for the asking. Plenty of BUD's (Big Ugly Dishes) too... George - Original Message - From: dgrapach [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Sunday, July 15, 2007 10:06 AM Subject: [Repeater-Builder] OFF Topic 2.4ghz Does anyone know where or does anyone have any primestar dishes they would want to part with in and/or around the Indiana county area. I am wanting to make a 2.4 ghz reapeater hop. These are the old oval fiberglass dishes. The finances are low on this project. Thanks for the off topic entry. Denny ka3sxq
[Repeater-Builder] (www.repeater-builder.com/pix/micor-ps-tpn-1106.jpg)
After searching the repeater-builder.com for Micor power supplies, then my emails to the beginning of 2006. I came across this which might be what I am looking for. Although, it is not in the repeater-builder pages. Any information would be appreciated. Tnx 73's, Jim? Kh6jkg. Check Out the new free AIM(R) Mail -- Unlimited storage and industry-leading spam and email virus protection.
RE: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750
Hello Eric, Skipp, and the Group!
I concur with rtc's PA fix scenario. That is real accurate on the
procedure and results that I experienced in the many PA repair issues I
have resolved in the majority of Mama Mo's Maxtracs, Gm300, and 1225
mobiles in use as-is or repeaters. A seasoned tech like you Skipp, IMHO,
is not going to need a road-map to fix the obvious.
I have encountered many Comm Sales People REPLACE repeaters and mobiles
with these types of PA failures. I guess that keeps us techs with
something to do and more refurbished product to sell.
Have Fun doing what we do best, Fixing Stuff!
I love my job {hobby}!
Charlie
It is not the class of license the Amateur holds, but the class of the
Amateur that holds the license.
Charles Mumphrey
Amateur Radio Station Kc5ozh
Kc5ozh Rowlett Repeater: 441.325 MHz + 162.2
Kc5ozh Dallas Repeater: 441.950 MHz + 162.2
Kc5ozh Rowlett Repeater II: 441.950 MHz + 110.9
Rowlett R.A.C.E.S. Unit 823
http://www.CharliesElectronics.com
http://www.hello-radio.org
http://www.emergency-radio.org
Original Message
Subject: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750
From: rtc_0001 [EMAIL PROTECTED]
Date: Sat, July 14, 2007 11:03 pm
To: Repeater-Builder@yahoogroups.com
It's not so much a defect as it is asking the rptr to do more than it
was designed for. It may be a 45 watt PA but in rptr use, medium to HD
rptr use, drop it down to about 25 to 30 watts out of the PA. Enjoy
what you get thru the duplexer. Asking for more will melt the PA.
The earlier units had a temp controlled fan that only came on when the
PA was about to melt. The next generation of power supplies came with a
switch to turn the fan on permanently.
You will probably be able to fix them without the manual. Most of the
time the PA transistor collector got hot, melted the solder the chip
caps moved (slid down the pcb due to gravity).
I repaired these on a regular basis without needing new parts unless the
damage literaly burnt the pcb around the collector lead. I removed the
chip caps, removed the solder on the collector tab trace resoldered
it all back in with silver solder. This, along with turning the factory
output down, made them last a long time even under HD casino use.
I think it took me maybe 45-60 mins to get it all apart, fix it,
reassemble, reinstall. Lots of times I did it in place at the customer's
premises. rtc
-Original Message-
From: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder@yahoogroups.com
Sent: Friday, July 13, 2007 11:08 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Motorola R1225 versus Kenwood TKR-750
Hi Eric,
SNIP
I just pulled three 1225 uhf repeaters from two different locations
and they all have the same failed tx pa problems. Wonder if there's
a minor pa defect problem (like there was in early version one tkr
repeaters) or it's just bad customer karma time. I've got to find
a service manual before we open them up...
cheers,
skipp
Re: [Repeater-Builder] (www.repeater-builder.com/pix/micor-ps-tpn-1106.jpg)
You came across what? Gary [EMAIL PROTECTED] wrote: After searching the repeater-builder.com for Micor power supplies, then my emails to the beginning of 2006. I came across this which might be what I am looking for. Although, it is not in the repeater-builder pages. Any information would be appreciated. Tnx 73's, Jim Kh6jkg.
Re: [Repeater-Builder] (www.repeater-builder.com/pix/micor-ps-tpn-1106.jpg)
At 08:41 PM 07/15/07, you wrote: After searching the repeater-builder.com for Micor power supplies, then my emails to the beginning of 2006. I came across this which might be what I am looking for. Although, it is not in the repeater-builder pages. Any information would be appreciated. Tnx 73's, Jim Kh6jkg. The repeater-builder/pix directory was a catch-all for a long time. Any pointers to it should have been updated long ago. Where did you find it? The Micor power supplies are on the Micor page. Go to http://www.repeater-builder.com/rbtip/micor-index.html and scroll down to Station Power Supplies and you will find the TPN1105 / TPN1106 schematic. The only difference between the two is the transformer and the primary wiring. The TPN-1105A can be wired for either 120 or 240vAC, but the reduced-cost TPN-1106A is 120v only. Mike WA6ILQ
Re: [Repeater-Builder] Re: 224 MHz PA fun and war stories
Gentleman, A word of caution with the new Mitsubishi power bricks. Please be sure to lap the bottom side of the brick flat using a belt sander with 150 grit and followed with 400 grit sand paper to achieve optimum smoothness. No one is sure what they were thinking with the bottom side of the module on the latest generation of bricks, but unless the heat sink contact is in the 100% range, you risk blowing up the module due to a ground and a heat resistance problem.
