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Ranger made radios RT1 invasion
- Thread starter Eldorado828
- Start date
it is comp tune 29. i know it not good on a radio. i do it to see how long a mosfet well last. the 13n10 been going on 2+ year maybe more and it is still good. for the mod.
the mod I do is the same as the ERF-2030 mod but a little more I us 13n10. the driver needs to be 2sc1957. and for the mod I do is c62 do not remove add a 400pf or up to a 500pf.put a jumper on r123. remove r55 and add 22pf up to a 110pf you need to do your own test to see what is the best for your radio for L14 don't remove slug remove one turn from copper wire. for the driver a 2sc2314 works. add a resister to R60 a .47ohm to a .1 ohm to get a low dead key do a v-power mod
the mod I do is the same as the ERF-2030 mod but a little more I us 13n10. the driver needs to be 2sc1957. and for the mod I do is c62 do not remove add a 400pf or up to a 500pf.put a jumper on r123. remove r55 and add 22pf up to a 110pf you need to do your own test to see what is the best for your radio for L14 don't remove slug remove one turn from copper wire. for the driver a 2sc2314 works. add a resister to R60 a .47ohm to a .1 ohm to get a low dead key do a v-power mod
What is it with all these Ranger radios? Why do they look like the Cobra 138 that I had in the 70's? Can't they improve on a 40+ year old design?
People want what they want. When a product breaks, or finally wears out they just want what they already had before the failure.
Henry Ford famously claimed to know what people needed, and ignored what they want. The quote "If I asked what they want they would have said a faster horse".
Progress has a give-and-take nature. Improving on a 40 year-old design sounds good, but only if the customers will buy it.
73
Henry Ford famously claimed to know what people needed, and ignored what they want. The quote "If I asked what they want they would have said a faster horse".
Progress has a give-and-take nature. Improving on a 40 year-old design sounds good, but only if the customers will buy it.
73
Hi folks. I've got a Ranger N3 with a set of blown RT1's., as well as one of the combiners or splitters (have to figure out which it is) and some resistors. I have a set of 13n10's and I've been reading this thread trying to figure out if I could/should use them? Sounds like I can use them if I want & it sounds like I may lose some wattage (peak?) but my main concern is which would be more long lasting. These Rt1's only lasted a few short months. Good swr.. It's for someone else. The owner said it was setup by GI Joe's & its my understanding that place just maxes everything out so that mightve had something to do w/it? Who knows? I didn't get a chance to look closely yet, but I'm guessing the finals in the radio are also RT1's. If so should the bias setting be about the same as with the older mosfets used? Haven't done this for awhile, but I'm thinking approx 3.5v?
Thanks for any insight. Oh, also, the owner said he was using this rig to hit a 12x2879 box (I think a fat boy or similar. Well, I don't know what the wattage (peak) from this radio with the RT1's, but I saw a video from Bells cb where a tuned one was doing near 450 pep, on am. If that's true, I wonder if that's not too much drive for the 12 pill? Im thinking it's too much. I think the radio should be dialed down (in the tuneup & the front panel variable pwr & the mic gain, to where its only hitting that 12 pill with a max of 200-250w to cruise & last long. Thoughts?
Thanks
Thanks for any insight. Oh, also, the owner said he was using this rig to hit a 12x2879 box (I think a fat boy or similar. Well, I don't know what the wattage (peak) from this radio with the RT1's, but I saw a video from Bells cb where a tuned one was doing near 450 pep, on am. If that's true, I wonder if that's not too much drive for the 12 pill? Im thinking it's too much. I think the radio should be dialed down (in the tuneup & the front panel variable pwr & the mic gain, to where its only hitting that 12 pill with a max of 200-250w to cruise & last long. Thoughts?
Thanks
I feel your pain. Good-quality IRF520s may hold up better than the 13N10s.
May.
A cheap chinese fleabay tester will permit you to measure the turn-on threshold voltage (Vth) of each MOSFET. Matching each one of a pair that share the same bias pot makes them last longer.
Gate-bias voltage is not set by voltage. Should be set by the current draw it controls. Easier said than done.
Here's the problem as I see it. The low-frequency MOSFET transistors used in this amplifier just don't tolerate SWR at all well. When driving an antenna, this is pretty clear-cut. The antenna system, coax and connectors must all be 100% solid.
But driving an amplifier is a different proposition. A SWR meter and coax jumper inserted between the amplifier's input socket and the radio will reveal what kind of hazard your amplifier represents. If your 12-transistor amplifier has a SWR under 2 to 1, you're probably okay.
Probably.
The other problem has to do with what happens when the amplifier is keyed by the driver's RF. The relay doesn't change over and go "click" until the radio is delivering RF power. That relay doesn't change from standby to operate instantly. There is a short but significant moment when the relay's contacts are in midair between standby and 'amplify'.
Needless to say the SWR during that short moment is really, really high. Not for long. But maybe for long enough.
Maybe.
Best solution is to key the amplifier directly from a relay jack on the radio. Giving the amplifier a head start so the relay starts to move when the mike is keyed should reduce that short burst of high SWR.
Did the N3 blow out driving this amplifier?
73
May.
A cheap chinese fleabay tester will permit you to measure the turn-on threshold voltage (Vth) of each MOSFET. Matching each one of a pair that share the same bias pot makes them last longer.
Gate-bias voltage is not set by voltage. Should be set by the current draw it controls. Easier said than done.
Here's the problem as I see it. The low-frequency MOSFET transistors used in this amplifier just don't tolerate SWR at all well. When driving an antenna, this is pretty clear-cut. The antenna system, coax and connectors must all be 100% solid.
But driving an amplifier is a different proposition. A SWR meter and coax jumper inserted between the amplifier's input socket and the radio will reveal what kind of hazard your amplifier represents. If your 12-transistor amplifier has a SWR under 2 to 1, you're probably okay.
Probably.
The other problem has to do with what happens when the amplifier is keyed by the driver's RF. The relay doesn't change over and go "click" until the radio is delivering RF power. That relay doesn't change from standby to operate instantly. There is a short but significant moment when the relay's contacts are in midair between standby and 'amplify'.
Needless to say the SWR during that short moment is really, really high. Not for long. But maybe for long enough.
Maybe.
Best solution is to key the amplifier directly from a relay jack on the radio. Giving the amplifier a head start so the relay starts to move when the mike is keyed should reduce that short burst of high SWR.
Did the N3 blow out driving this amplifier?
73
The latest radios with SWR protection/monitoring usually set at 2.0 SWR will shut off when they are keyed. Friend of mine had a Fatboy 1x6 with staged driver that was shutting a Lincoln 2+ V3 off as soon as it was keyed. He said the amp worked fine with a Galaxy Saturn.
Anyway, I called my tech friend, and he made a custom jumper that goes between radio and amp input. All the tech had was LMR 400 at the time, so I had him make it, and it ended up being around 15 feet long. Can't remember the exact measurement. He was using a formula with velocity factor and whatever else. Anyway, jumper worked great, and the radio SWR monitoring was showing round about what I measured with an antenna analyzer. No more radio killing power to finals.
Nomad....thanks for all the info.. Having 2 problems w/the forum. 1) the way it displays on my phone is very confusing & not very intuitive & 2) I tried several times to reply to all you said, from the emails I rcvd. Everything I sent to you bounced as I guess the emails are "no reply". I could've sworn in the past I was able to reply that way but maybe not. I DID answer your last question about YES, the 12 pill amp was indeed on. I don't know if I still have any ooies of all the stuff I replied to you with, which bounced. The main question, and apologies if within your initial response to me, you answered this question, but I'm still trying to figure out if I should order a set of RT1's or to use the 13n10's I have or to find a "good set" of irf520's? I got the impression you're not too impressed s/the RT1's & I know you said the right irf520's may hold up better, so if that's the case, which irf520's do I need to get? Vishay? What are the ones that end in an "N"? Is that the Vishay or some thing else. Also, how critical would you say is the need for a way to overcome that delay in the relay issue? I'm guessing that since I let you know that yes, the 12 pill was on when this happened, that it's critical that I do something about it. Do I need to hook up a key switch from the relay of the amp so that the owner always must push the button 1st BEFORE keying the mic, when amp on? In my now lost last reply, I had mentioned that I used to have an mfj259b but due to my financial situation I had to sell it. Somewhere along the line I came up with an mfj antenna bridge but it's very confusing to me on how to use it. Even the "manual" is confusing. I aay this because I want to personally test the owners "match" between his radio & amp as well as to antenna. He said they were good but I don't trust that, esp since the amp blew. Do you feel it's enough for me to test the swr between the radio & amp, or should I be concerned with impedance, capacitance, reactance??? I went way too long on my lost last email so I think I should stop here.
Thanks much for your time
Mr Eldo...
HI Mr Eldo... I had been, a few days ago, messaging w/nomad re: RT1 & I had more questions but no further comments so I thought it was how my phone doesn't play too great w/this forum or some other reason caused my post to not make it here, but now I see it did.. In any event I'd like to take this up with you a bit as you are the only one I so far could find, to state what the RT1's are and I want to throw in a couple thoughtz I had about it and also ask for a little help on a repair. My thinking is that is companies like Ranger decide to choose some transistor to use and buff the #s off & restamp with RT1 or whatever, well, when you think about it, anyone could be using whatever mosfet they want, assuming it's a workable drop in and stamp whatever they want on it and no one is the keener as to what is actually underneath, right? I don't know if Ranger is rebranding the RT1 as per any agreement they might have with the manufacturer, or if they're just doing it cuz they can? Nor if any such agreement is even legally necessary? So if they can do it anyone can and DO the same... Add to it, I have a set of blown RT1's. I say RT1's, because the radio came from Ranger w/them installed & they say "RT1" on the devices. Of course that doesn't mean that somewhere along the line substitutions were or weren't made. And these blown RT1's have what I call a really crummy RT1 stamp on them. Obviously the orig manufacturers stamp buffed out and stamped RT1 using a very cheap, almost child's toy stamp. And...looking at the set of 8 that I pulled from this radio, it's obvious that not all the stamps are even close to being equal in quality. I'm attaching a good ex of this from 3 of them I picked out where 1 has a fairly decentooking stamp, although still far short of what you'd expect professionally from Ranger and the other 2, to me, look like they were stamped by a McDonald's toy, no exaggeration. So once I saw that and spoke to my supplier for replacement parts, getting his input, is when I came to this realization that regardless of where the rebranded parts come from, ie, Ranger, Barkett, Lesco, wherever, they could be anything from anywhere or anybody and no one the wiser (u less they had 1st hand knowledge or did extensive testing and/or pulled them apart to get to the substrate & actual circuit, using a microscope and looked for telltale signs of its origin. I mean, imagine Ranger sending out to sellers like Barkett, these (see pic) crappily marked mosfets. This means anyone could buy up a bunch of cheap China irf520 for like 10 or 20 cents ea in quantity and easily buff them out and apply the RT1 # on there and sell for say $2 ea. Barkett sells them for $3.
All that said, so then how do you know the ones you got, which are marked as the IRFZ24N are actually what Ranger uses for the RT1? The only supposed supplier I know of is Barkett & maybe Lesco I heard? I don't know which supplier your came from but they initially were unmarked so who knows if they are the same as what Ranger is using? And then your friend sent some more which are the IRFZ24N but how do you know that's what Ranger uses?
Now, the plot thickens...
Before I went and ordered a set from Barkett (eagle one radios), I decided to check with my large American wholesale supplier I've used d for over 20 yrs. I asked if he had any RT1's. He said yes he thought so but needed some more time to check. I thought that was odd but it turned out there was a good reason for that. He had a small quantity listed in his computer system but they didn't seem to be there where they should be in the stock dept. It took a couple days for him to figure it out and get back to me. He then explained that over a year ago he had a request from a texas customer for some RT1's. He didn't have any or know of them so he wound up putting in an order for them, I guess from one of their regular suppliers in China? He was told that the transistors they were sending him were RT1's. He's just a salesman so he was done with it at that point. So I bought a set of what he said were RT1's but then they sent me a digital invoice, it said IRFZ24NPBF on it. I'm like wtf? I became very concerned about it as I had already looked at bells cb N3 YouTube video where it shows the pep at close to 450w. And the owner of the radio told me that before it blew up it was showing over 500 on his meters (no dummy, PDC600 type meter). I told him forget that, no way. But then I saw the bells video w/close to 450. The point is, I don't know what the IRFZ24NPBF were compared to the orig RT1's or what kind of output they had. So I don't know whether to use the IRFZ24NPBF or throw in a set of irf520 vishay or I had a set of 13n10's on hand or maybe just order from Barkett?
I spent the next few days speaking to my supplier, Barkett, Eric Lewis, someone I know from galaxy, the boss at bells cb, etc, trying to find out what the hell the RT1's were and if the IRFZ24NPBF were indeed one & the same. No one knows nothing as you might expect. I learned that it is Ranger & Ranger alone who is rebranding the RT1 from whatever orig mosfet. I sent them an email asking about it and so far and not surprisingly, they haven't replied. Barkett will not divulge anything if they even know and say only that they order their RT1's from Ranger in Malaysia. Mr Lewis is no longer involved w/Ranger and doesnt know what the RT1's actuality are.
Which brings me back to your post which I had actually seen before I ordered my RT1's & then saw the invoice that said irfz24npbf, not RT1... I'm thinking maybe they are irfz24npbf but who knows what anything is anymore when a mega company like Ranger can buff off part #s & put whatever they want on there?
I spent the next several days trying in vain to positively find out what the RT1's actually are and if the IRFZ24NPBF is the same thing. Because I saw the bells cb youtube video of the N3 doing 450w peak and the owner of the N3 I have said b4 it blew up it was doing well over 500 (but that's on his pdc600 type meters w/no dummy). So I didn't want to use irf520 or 13n10's.
I contacted my supplier, Eric Lewis, someone I know from galaxy, the guy from bells cb, Barnett and Ranger. No one know anything or will divulge if they knew Ranger didn't even return my email.
So I decided to go ahead w/the IRFZ24NPBF's & hope for the best. (I had actually seen your post about the IRFZ24N early on, before I saw my invoice but didn't pay much attention to it until I rcvd my irfz24npbf's and all the rest, until today I remembered to go back & try to find your post about the IRFZ24N.
I hoped to have the job done by now but ran into a few addtl problems.... One of the ferrite transformers was toast. I think it's a combiner. And both 100 ohm resistors bad. They are hi heat components (maybe metal oxide?) and both still looked pretty good (except for the stripes changed color). To my surprise, the one on the output side (w/the burnt torroid) was open. The other one was over 200 ohms measured. Using a torroid from a texas star and the resistors they come with.
Ran into the inevitable lifted board pads for the transistors. About 4 of them. My eyes not so great anymore so I'm working on repairing those..
My last problem is the biasing can't find any alignment for this amp board. I was gonna set the gate voltage at around 3.5 v, like most mosfet radios say to do, but I see where nomad says that's wrong way to go & to set the drain current for more accuracy. I heard that Ranger says same thing to do. But I'm not sure of the setting for one thing. I heard it should be 50mA per mosfet & about 400mA total per side but I know that's wrong because the math doesn't add up. Maybe 200mA per side? And also I don't know quite how to measure the current on this amp. I know it's done in series with meter & I know how to do it on radios like a 148/grant/xl & other radios with the pullout jumper board but I don't know how to do it on this amp if there is a special way. I guess it should be done in ssb, unmodulated? I could use some help w/how to...
One last thing is that when I opened up the amp, one of the small plugs was unplugged. I don't know yet what that plug is for or if it is supposed to be unplugged? I can give you the board location if that will help...
Hope you found this post of interest & can help me with the issues I noted.
Ok, let me try it here...
Oops, as usual I forgot to attach the pics I promised so here they are. Remember, this is what comes from Ranger! Also included a couple of the IRFZ24NPBF that I installed & for comparison of the markings, an irf520 & a 13n10. Hope I did it right. Not sure if I ever uploaded any pics here before..
LOL, I got an error for too large. It says characters but it must be the hi rez pics. So I'll retry 2 at a time.
Well, that didn't work either so I must have somehow added this post to the last one & gone over the limit. I don't know how to work this forum w/this phone too well. I guess I have to save this, then erase this part, then make a new post. I thought I did but guess not...
Oops, as usual I forgot to attach the pics I promised so here they are. Remember, this is what comes from Ranger! Also included a couple of the IRFZ24NPBF that I installed & for comparison of the markings, an irf520 & a 13n10. Hope I did it right. Not sure if I ever uploaded any pics here before..
LOL, I got an error for too large. It says characters but it must be the hi rez pics. So I'll retry 2 at a time.
Well, that didn't work either so I must have somehow added this post to the last one & gone over the limit. I don't know how to work this forum w/this phone too well. I guess I have to save this, then erase this part, then make a new post. I thought I did but guess not...
Attachments
Geeez... I forgot something else (a pic of the plug) and when I hit post, it disappeared. This forum don't like my s8 phone at all. I had said that I 4got2 up the pic of the plug I had mentioned finding unplugged when I opened the amp cover. It's J9 and it appears to say "TX" up above it. I don't understand how this can be. I'm sure I found it unplugged before I unplugged the other plugs. I'll have to ask the owner if he had anyone else look at it before he gave it to me, but I don't think so. I don't see how this is possible?
