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Bob,
The IRF510 and RD15HVF1 can both be used in this design, but are not really electrically equal, nor are they near the same cost (if you can find the RD15HVF1 part). For this transmitter, the RD15HVF1 would be a better part to keep the output more consistent across the bands. The IRF510 was designed as a high-speed high power switch. The RD15HVF1 was designed to be used as a VHF power amp. The IRF510 has a higher voltage capability. The RD15HVF1 has better gain at higher frequencies. The BIG difference is in the price. Doing a quick search on the internet gave an eBay price of $6.00 for the RD15HVF1 vs a Mouser price for the IRF510 of $0.98 for quantity one. Since there are other parts of the uBITX that limit the power output at 10meters, the advantage of the higher frequency of the RD15HVF1 is negated to a large extent. You could spend the $12+ shipping to experiment, but not really worth it to me. It will not solve any of the earlier boards (v3, v4) purity issues so you are spending money for, at best, a few watts at the higher end of the range. You can get some of the frequency advantages by increasing the voltage to the finals in the uBITX with the IRF510s, the design for the RD15HVF1 is 12.5volts. The side effect of increasing the voltage using the IRF510s is that the power goes up across all of the bands, not just the higher ones (for some this is a good thing). Above are my interpretations of the datasheets I found and could be in error. I just wanted to point out that they are not truly the same, just that both will work in the uBITX as designed. As always I am happy to get any feedback or corrections so that I can continue to learn about this hobby. 73 Evan AC9TU |
Bob,
Yes!!! When my mother bought her first colour television in the '70s, I was watching through the grids.The circuit boards were the same, only the selection buttons were different.There was a price difference...for the same TV with a different brand!!!! The salesmen didn’t like it when you knew them. Even less now when you say you have checked on the net now (Especially auto mechanics car) LOL cdt |
I just KNEW there was a logical and simple answer to this. Same item electrically but in a different "box." Bob � KK5R
On Sunday, November 22, 2020, 6:13:09 AM EST, Raj vu2zap <rajendrakumargg@...> wrote:
Yes, you can use one or the other but not both. The pinout is different so Farhan has provided for both solder pads. Raj At 22/11/2020, you wrote: >hello, >I had already asked the question, but I did not get an answer >on the schematic of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage >We see an IRF510 and a RD15HV in //. >Maybe it’s a choice of transistor? You put one or the other? >I don’t quite understand the diagram |
It is common for a draftsman to use the double-slash ("//") tp denote a line that continues. Some use the double-tilde ("~~") instead. It is done to denote a "broken line" where it only means that a much too long line lengthens over a section of the drawing. I is an 'unspecified length' ... nothing more. I can, however, see it as an indication that one's particular radio may be opened and one or the other transistor may be found installed as the final transistor since the two may be electrically identical but made by different manufacturing firms and the particular firm's identification marking may be found on that transistor. It could be that the manufacturer of the transistors is the same, the marking only is printed on the transistor as bought/contracted by the buyer. At one time there were over 250 brands of tires offered in America and only 17 manufacturers. When I worked many years ago in a radio-TV shop, there was a l17-inch BW TV that when opened was found to be identical but sold under four different brands; even the diagrams used the part numbers of the different brands but the schematic was identical. Japan at one time had a catalog of cassette tape drives which were offered to different sellers so they could be put in their cases and sold as THEIR cassette players, many buyers not suspecting that the cassette they purchased was identical to the one sold for XX dollars less/more but they chose the machine they bought because the box it was in appealed more to their likes and taste. We live in a sometimes confused world. Bob � KK5R
On Sunday, November 22, 2020, 6:07:19 AM EST, Gerard <kabupos@...> wrote:
hello, I had already asked the question, but I did not get an answer on the schematic of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage We see an IRF510 and a RD15HV in //. Maybe it’s a choice of transistor?You put one or the other? I don’t quite understand the diagram for traduction fron Italien, try reverso Avevo già posto la domanda, ma non ho avuto risposta sul piano dell'ubitx 6, ci sono come 2 transistor montati in parrallele sul piano finale Vediamo un IRF510 e un RD15HV in parallelo. Potrebbe essere una scelta di transistor?Si mette uno o l'altro? Non capisco lo schema Loris, se capisci questo, è che Reverso non funziona troppo male cdt |
Yes, you can use one or the other but not both. The pinout is different so Farhan has provided for both
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solder pads. Raj At 22/11/2020, you wrote:
hello, |
hello,
I had already asked the question, but I did not get an answer on the schematic of ubitx 6, there are like 2 transistors mounted in parrallele on the final stage We see an IRF510 and a RD15HV in //. Maybe it’s a choice of transistor?You put one or the other? I don’t quite understand the diagram for traduction fron Italien, try reverso Avevo già posto la domanda, ma non ho avuto risposta sul piano dell'ubitx 6, ci sono come 2 transistor montati in parrallele sul piano finale Vediamo un IRF510 e un RD15HV in parallelo. Potrebbe essere una scelta di transistor?Si mette uno o l'altro? Non capisco lo schema Loris, se capisci questo, è che Reverso non funziona troppo male cdt |
IW4AJR Loris
Hello Todd
It isextremely difficult to translate Italian into English ... Italian is a complex and unique language in concepts and definitions, English is too simplistic a language to express certain concepts ... Do you want an example: tu sei -> you are voi siete -> you are tu hai -> you have voi avete -> you have it is enough for you ?....Loris |
Bitx40 PC Board Image Please
#bitx40
After some years of lying fallow, I have found my round tuitt to assemble Farhan's bitx40. I need to make Allard's recommended mods. It would greatly help me if some kind person could email me images of the top and bottom of the PC board. Many thanks in anticipation.
Kevin VK3DAP / ZL2DAP |
Thanks, Gordon. I'm building from scratch so I didn't have a board to look at, and I wasn't smart enough to look at a picture or the layout file. 73, Todd K7TFC On Sat, Nov 21, 2020, 6:30 PM Gordon Gibby <docvacuumtubes@...> wrote:
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I've seen that on other schematics. Where there are more than one with the same arrangement of accompanying resisters, etc., the line is dashed and the notation "Q1, ... Qn" is written above the line to designate the transistors in the string.. It's done to conserve space on the paper and to avoid unnecessary confusion. Want to talk about confusion with schematics? I worked for a machine tool company in New York for a year and one engineer owned his own machine tool company in the Philippines previously and he designed an automatic system for cutting rods into threaded shafts with all kinds of beveled areas, reliefs and retaining slots. The drawing for the machine was 40-ft long... The machine cut a shaft automatically in less than half an hour that took four times that when done by a human and with much more precision. Such machines are fascinating to watch, much like the first time you see a plotter drawing up a written document with fancy fonts, etc. I know a draftsman/designer (WB4RVN) who can draw script that looks like it was done by a machine. I'm sure there are others equally talented. These people are artists in their own right. Calligraphy is indeed an art. Bob � KK5R
On Saturday, November 21, 2020, 9:31:00 PM EST, Gordon Gibby <docvacuumtubes@...> wrote:
Yes, they are in parallel. I was confused the first time I saw that with an earlier schematic years ago and checked it out. (look at the actual board)� On Nov 21, 2020, at 20:21, Mick <Mgsebele@...> wrote:
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Yes, they are in parallel. I was confused the first time I saw that with an earlier schematic years ago and checked it out. (look at the actual board)�On Nov 21, 2020, at 20:21, Mick <Mgsebele@...> wrote:
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Re: Email still coming in no email button selected
I have found that some browsers when you hit the Save button and it does not work, hold down the Shift button when you click Save and the system accepts it. Worth a try. Bob � KK5R
On Saturday, November 21, 2020, 8:55:15 PM EST, jaytee1@... <jaytee1@...> wrote:
Dave, Thanks all suggestions are great. That was already tried and Admin gave it a try, but its a weird anomaly. As suggested I left the group and re-joined but the issue continues. |
Re: Email still coming in no email button selected
David Gillooly
I haven't followed your thread so please excuse if my suggestion has been offered.
After you check the no subscribe button scroll down the page, and hit the save button. I don't know if this is necessary but may be worth a try. Dave, AA6RE |
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