[Repeater-Builder] Re: Mot. IC cross reference
--- In Repeater-Builder@yahoogroups.com, "Eric Lemmon" <[EMAIL PROTECTED]> wrote: > > I searched MOL to see if "61L23" appeared anywhere within a current part > number, but found nothing. If you can describe the board it came out of, or > post a picture of the board, that may help. > > 73, Eric Lemmon WB6FLY > > > -Original Message- > From: Repeater-Builder@yahoogroups.com > [mailto:[EMAIL PROTECTED] On Behalf Of wa9zzu > Sent: Wednesday, January 17, 2007 10:04 AM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Mot. IC cross reference > > I need a commercial cross reference to a Mot. IC #61L23. Can anyone > help? Unknown the board number. Got no help from IC suppliers. > Thanks, wa9zzu. > The IC's came from K9MDM's wharehouse liquidation sale last November and I have no idea where they were used. The parts are 8 pin DIP with the no. 61L23 marked and mfg'd by RCA. I've tried connections using the generic 741 & dual op amp and was unable to get any voltage or signal out. I'm stumped. wa9zzu
[Repeater-Builder] Re: DB-304DL antenna
--- In Repeater-Builder@yahoogroups.com, "Kevin Thomas" <[EMAIL PROTECTED]> wrote: > > Does anyone have or no where I can get the paper-work/manual for a DB- > 304DL antenna. I called and talked to the tech guy's at DB Products. > They said that they no longer have any info on this antenna. > > It is a 16 pole array for VHF high band and looks like a DB-420 except > bigger, a lot bigger. > > W5KGT > Hmmm I have the DB304 info in my old DB catalog. What it shows is the L version, which places all dipoles in line with each other. And the D version, which basically splits the DB304 into two, with separate feedlines, and 3.2dbd gain each. The DB304 is rated at 6.1 or 6.7dbd gain, depending on whether the dipoles are in line or at 90deg with each other. So, I'm not sure why you have a DB304DL with 16 dipoles, 8 levels I assume. The gain figures and the picture in the catalog I have both indicate an antenna with 4 levels, each level having two dipoles side by side, like a DB408. Could you have two 304DLs on one long mast? Check the model number again, and check for more than one feedline on there somewhere. Laryn K8TVZ
RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
> Even the common plug-in circuit breakers made by Square D, > Cutler-Hammer, and others are available in high-inrush > versions- but you > won't find them at Home Depot. Yeah, I know. I've always heard them called "hi-mags", meaning higher magnetic (current) trip point as compared to standard breakers, yet still have the same thermal trip point for longer-term protection. I seem to recall larger industrial breakers having a built-in delay for inrush current trip protection. You're the power guy, you tell me :-) > In the specific case you cited, it may be that the 20A > circuit was shared > with other equipment. That's not good. In many cases, no, that wasn't the cause. But I agree that sharing a circuit among multiple tenants is never a good idea, regardless of the average or peak current draw. You never want one bad apple to spoil the bunch. And I only buy electrical supplies at the Depot when the good electrical supply places are closed, like on a Monday, or at 10PM the night before a job. I don't think I need to get into the reasons why... --- Jeff
Re: [Repeater-Builder] Re: Power Suplies going up in smoke...
At 1/17/2007 11:37 AM, you wrote: > > A long time ago I happened to find a crowbar "bar" made by Lambda at the > > local TRW swap meet. I added it to a supply without built-in OVP to add > > said protection to the equipment. I wonder if similar devices are > > commonly > > available somewhere? That & a fuse on the output of an SEC-1223 & I think > > I'd feel comfy using it at one of my sites. > > > > Bob NO6B > >Bob, > These crowbar circuits are quite simple to design and build. They >usually consist of a large SCR, a zener diode, one resistor, and an optional >capacitor. Of course a fuse upstream somewhere is a great idea, too. A heat Yes, I know - I've designed & built a few for some pricey amplifiers we use at work. I'm just looking for something I can slap on an existing P.S. without having to worry about building, packaging etc. > >sink is not necessary because of the very short duty cycle. Actually, some heat dumping is required since when they fire they sink several amps of current & do have a finite voltage drop across them. Not much, but enough to need a little heat sinking. Bob NO6B
RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
Jeff, More likely, the 20A panel breaker was a garden variety that was designed for residential and light commercial lighting and receptacle applications. Most manufacturers of power-distribution circuit breakers offer models with time-current curves tailored for specific applications, including high-inrush models with a hydraulic dashpot made especially for transformer protection. Such brands as Airpax, Carlingswitch, and Heinemann come to mind. Even the common plug-in circuit breakers made by Square D, Cutler-Hammer, and others are available in high-inrush versions- but you won't find them at Home Depot. In the specific case you cited, it may be that the 20A circuit was shared with other equipment. That's not good. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Jeff DePolo Sent: Wednesday, January 17, 2007 9:52 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered) Maybe they think they need to go that big to handle the inrush current? A properly-sized fuse should be able to handle the inrush current without blowing (even if it's not slo-blo). However, I can't say the same for circuit breakers in the panel. Don't know how many times I've tripped a 20A panel breaker by turning a 50A Astron on... --- Jeff
RE: [Repeater-Builder] Mot. IC cross reference
I searched MOL to see if "61L23" appeared anywhere within a current part number, but found nothing. If you can describe the board it came out of, or post a picture of the board, that may help. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of wa9zzu Sent: Wednesday, January 17, 2007 10:04 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Mot. IC cross reference I need a commercial cross reference to a Mot. IC #61L23. Can anyone help? Unknown the board number. Got no help from IC suppliers. Thanks, wa9zzu.
RE: [Repeater-Builder] DB-304DL antenna
Nate and group, Sorry, a 304 has 8, a DB-228 still only has 8 elements and is basically two DB-224's (4 dipoles) stacked vertically. The 304 looks a little like a DB-410 in that the dipoles are opposite each other still on a 20 something foot mast. The DB-228 still has 8 elements but spread out on a 40 something foot mast. They both have their places, I don't think DB makes the 304 any longer, too bad. In my paging days a DB-304 had a lot better lobe straight down and would cover tall buildings in a single bound where a 224 seemed to have a null right under the antenna. The designers of the 304 antenna never understood that one. I put a DB-228 up for a customer a couple years ago, they said they talked places where they never have and are very happy compared to the old antenna. I am planning on putting one on my tower as the receive antenna since a new customer is coming on with a high band system. It will help my Ham systems also! Paul -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Nate Duehr Sent: Wednesday, January 17, 2007 6:55 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] DB-304DL antenna On 1/16/07, Kevin Thomas <[EMAIL PROTECTED]> wrote: > It is a 16 pole array for VHF high band and looks like a DB-420 except > bigger, a lot bigger. 16? Wow... yeah... Big. Nate WY0X Yahoo! Groups Links Visit http://www.ourphoneList.com";>OurPhonelist.com It's free and you'll never lose track of a phone number again! -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.16.13/632 - Release Date: 1/16/2007 4:36 PM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.16.13/632 - Release Date: 1/16/2007 4:36 PM Visit http://www.ourphoneList.com";>OurPhonelist.com It's free and you'll never lose track of a phone number again!
Re: [Repeater-Builder] DB-304DL antenna
On 1/16/07, Kevin Thomas <[EMAIL PROTECTED]> wrote: > It is a 16 pole array for VHF high band and looks like a DB-420 except > bigger, a lot bigger. 16? Wow... yeah... Big. Nate WY0X
[Repeater-Builder] Re: Power Suplies going up in smoke...
> A long time ago I happened to find a crowbar "bar" made by Lambda at the > local TRW swap meet. I added it to a supply without built-in OVP to add > said protection to the equipment. I wonder if similar devices are > commonly > available somewhere? That & a fuse on the output of an SEC-1223 & I think > I'd feel comfy using it at one of my sites. > > Bob NO6B Bob, These crowbar circuits are quite simple to design and build. They usually consist of a large SCR, a zener diode, one resistor, and an optional capacitor. Of course a fuse upstream somewhere is a great idea, too. A heat sink is not necessary because of the very short duty cycle. Probably Googling "crowbar circuit" would reveal many options. 73, Al, K9SI
Re: [Repeater-Builder] Mot. IC cross reference
There would be some additional numbers ahead of that, which would turn it into a real Motorola part number. For example, if the part was a 51-81261L23, they'd label it as 61L23, leaving off the 51812 prefix digits (that's not the right number). They do this to many of their transistors too. If we knew what it came out of, perhaps someone has a manual and can find an IC with that number. Bob M. == --- wa9zzu <[EMAIL PROTECTED]> wrote: > I need a commercial cross reference to a Mot. IC > #61L23. Can anyone > help? Unknown the board number. Got no help from IC > suppliers. > Thanks, wa9zzu. Don't pick lemons. See all the new 2007 cars at Yahoo! Autos. http://autos.yahoo.com/new_cars.html
[Repeater-Builder] Mot. IC cross reference
I need a commercial cross reference to a Mot. IC #61L23. Can anyone help? Unknown the board number. Got no help from IC suppliers. Thanks, wa9zzu.
RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
At 1/17/2007 11:41 AM, you wrote: >Keep in mind that most of the over voltage protection circuits that use a >SCR on the output (Astron) require you to turn off the supply to reset >the protection. Not a good thing for a remote repeater if you have a >spike that simply triggers the SCR. Astron has another circuit option >that corrects this problem. > >Gran K6RIF Yes, but "correcting" the problem means that a fault in the power supply's regulator could result in the OVP circuit going into a continuous trip-reset cycle. This could let voltage spikes through on the resets. Every time I've had a crowbar trip, it was due to some sort of failure in the supply itself. Sometimes it's the OVP circuit itself, but other times there was a more serious problem (regulator failure, bad filter capacitor, etc.) I'd rather have the output remain shunted until I can check it out myself. Bob NO6B
RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
Keep in mind that most of the over voltage protection circuits that use a SCR on the output (Astron) require you to turn off the supply to reset the protection. Not a good thing for a remote repeater if you have a spike that simply triggers the SCR. Astron has another circuit option that corrects this problem. Gran K6RIF At 09:51 AM 1/17/2007, you wrote: Bob sed: > > A long time ago I happened to find a crowbar "bar" made by Lambda > > at the local TRW swap meet. I added it to a supply without > built-in > > OVP to add said protection to the equipment. I have some of those in a box somewhere if anyone is looking for any. Some are adjustable voltage, some are fixed. Skipp sed: > Astron designed their crowbar circuit to short the supply output. > The shorted output protects the user equipment and tries to > force the AC Mains fuse to open through excessive transformer > primary current draw. If the regulator is working right, it will go into current limiting, rather than blowing the fuse. This is typically what you find when you get to the site to figure out why your Astron-powered repeater isn't working... > The bad news is found when modest size power supply - ac mains > fuses are replaced with excessive large current values (the trusty > 25 or 30 amp 3ag fuse everyone seems to have a lot of...). Maybe they think they need to go that big to handle the inrush current? A properly-sized fuse should be able to handle the inrush current without blowing (even if it's not slo-blo). However, I can't say the same for circuit breakers in the panel. Don't know how many times I've tripped a 20A panel breaker by turning a 50A Astron on... --- Jeff
Re: [Repeater-Builder] For Sale GE MVP Repeater
Information for AP-50 problem has been solved. Thank you Gary K2UQ
RE: [Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
Bob sed: > > A long time ago I happened to find a crowbar "bar" made by Lambda > > at the local TRW swap meet. I added it to a supply without > built-in > > OVP to add said protection to the equipment. I have some of those in a box somewhere if anyone is looking for any. Some are adjustable voltage, some are fixed. Skipp sed: > Astron designed their crowbar circuit to short the supply output. > The shorted output protects the user equipment and tries to > force the AC Mains fuse to open through excessive transformer > primary current draw. If the regulator is working right, it will go into current limiting, rather than blowing the fuse. This is typically what you find when you get to the site to figure out why your Astron-powered repeater isn't working... > The bad news is found when modest size power supply - ac mains > fuses are replaced with excessive large current values (the trusty > 25 or 30 amp 3ag fuse everyone seems to have a lot of...). Maybe they think they need to go that big to handle the inrush current? A properly-sized fuse should be able to handle the inrush current without blowing (even if it's not slo-blo). However, I can't say the same for circuit breakers in the panel. Don't know how many times I've tripped a 20A panel breaker by turning a 50A Astron on... --- Jeff
[Repeater-Builder] Re: Power Supplies going up in smoke (non filtered)
> [EMAIL PROTECTED] wrote: > Unfortunately, I got a reply from Samlex saying the OVP is > of a feedback type, not a crowbar, which explains Jeff's experience > with the SEC-1212. Not so good... > A long time ago I happened to find a crowbar "bar" made by Lambda > at the local TRW swap meet. I added it to a supply without built-in > OVP to add said protection to the equipment. I have seen a number of small crow-bar pc daughter boards tacked onto various "Power One" (a brand name) type power supplies. They are easily copied or even lifted off the original supply for use in other locations. > I wonder if similar devices are commonly available somewhere? They are but nothing comes to mind right away... You might check with Kitsrus, Jameco, Electronics Rainbow, Marlin P. Jones and a few other kit mfgr/retailers to see what they offer. If not I can and would share some of my notes if you want to "roll your own". > That & a fuse on the output of an SEC-1223 & I think > I'd feel comfy using it at one of my sites. > Bob NO6B The key points are location, function & size. Where will the crowbar be placed? What will the crowbar do to everything on the dc bus at a fault condition? What happens after the fault condition goes away and or remains? Does the crow-bar device/circuit have a large enough capacity. Astron designed their crowbar circuit to short the supply output. The shorted output protects the user equipment and tries to force the AC Mains fuse to open through excessive transformer primary current draw. The bad news is found when modest size power supply - ac mains fuses are replaced with excessive large current values (the trusty 25 or 30 amp 3ag fuse everyone seems to have a lot of...). Not enough current draw through the faulted secondary side of the supply to open the wrong size installed ac mains fuse. Somethings got to give... and it's often very hot when it does. cheers, s.
Re: [Repeater-Builder] For Sale GE MVP Repeater
What do you consider reasonable? - Original Message - From: "Vincent Caruso" <[EMAIL PROTECTED]> To: ; <[EMAIL PROTECTED]> Sent: Tuesday, January 16, 2007 9:40 PM Subject: [Repeater-Builder] For Sale GE MVP Repeater >I just took out of service an MVP repeater on the 464.XXX /469.XXX it > is already duplexed and wired for a Zetron model 38 controller. This > radio was privately labeled for Logisticon by GE and is in a blue case > with just an on off switch on the front and the mic connector on the side. > > It was in use until 1/12/07 and in good working condition the only > reason we pulled it was to replace it with a narrow band complaint > repeater. > > The tx was set to low power and drove a continuous duty Henry amp with > no problem. > > Looking for reasonable offers. > > Make me an offer I can't refuse + shipping and it's yours > > If you would like pics please contact me off the list > > Thanks > Vince > > > > > > > > Yahoo! Groups Links > > > >
Re: [Repeater-Builder] still looking for
Why not just order the basic kit from NHRC? These are inexpensive and the rest of the parts could be picked up from another supplier. Paul --- Steve <[EMAIL PROTECTED]> wrote: > Hi > Iam still looking for a cheap NHRC controller to use > on a preoject, Iam in the UK. If you have one please > mail me direct with a price. > My appologies to anyone who has offeredme one and > had no reply, this is probably due to my spam filter > as it will not > asccept certain ISP,s such as MSN or earthlink, > sorry but I > have to do this due to huge ammounts of spam > > 73 > > Steve Need Mail bonding? Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=list&sid=396546091
[Repeater-Builder] still looking for
Hi Iam still looking for a cheap NHRC controller to use on a preoject, Iam in the UK. If you have one please mail me direct with a price. My appologies to anyone who has offeredme one and had no reply, this is probably due to my spam filter as it will not asccept certain ISP,s such as MSN or earthlink, sorry but I have to do this due to huge ammounts of spam 73 Steve
