Gi 7b power supply Anode supply was about 850 V on The GI-7B tubes were installed and the determination was made to replace the old change over relay with a smaller and faster unit. The 2 sec. The anode fins can only be described as substantial, they are also silver plated. Would say the thermal madness and runaway temp of the actual pre needs a look too. The GI-7B with a heat sink and the GI-70B with no heat sink. It was mounted much lower in the same location. Quality K4POZ tube socket & bias board 5. As mentioned, my SB-200 nets me a 800 watts with its improved power supply board. Test the relays by applying 12v from a bench power supply. Used custom GI-7B sockets, bias board and schematic provided by K4POZ. That was the fun trip 🙂 : On of the anode tranformers for it: GI-7B VHF amplifier built by me, never used it in the real communications, we started using DMR and I forgot about it: I was using GS-31B radiator on the GI-7B lamp. 9 V. Replace power supply diode/cap board with Far Circuits board and new, smaller caps 3. DESCRIPTION A 144 MHz GI7B Power Amplifier This construction article appeared in 1987 in Radiotechnika magazine (Hungary). 4 kV on load. 0: GI-7B (2) 57: 14 og 28MHz testforsterker [In Norwegian] Appears to be a test amplifier: 5W: 16. The bias circurit. 3. The valve has few connections, it is a directly heated triode. Our portfolio includes a vast variety of products and services for your power plant needs. Replace 4, 572B tubes with 2, GI-7B tubes 2. Filament and 12vdc power supplies. At a plate potential of 2000 Volts the gain is around 13 dB and the efficiency about 60% on 144MHz when build in grounded grid. This cable/plug assembly is actually from an old PC power supply fan; the header is from the same supply (. I was surprised when the SB-230 measured in at a good 900 watts with its original power supply. This foto from internet. The GS I bought my MLA-2500 at a local swapmeet for $85. slow start board is mounted. Use current limiting resistors and other methods to protect your brand new power supply. 00 delivery. The GI-7B, a 12. For details on GI-7B tube socket construction, click HERE. The GI-7"b" is available in two variants differing in the type of cooling: the GI-7b with a heat sink for forced air cooling and the GI-70b with no The OTK stamp is a quality stamp of the Russian army and the valve is a GI-7B in the Cyrillic. Apr 7, 2023 · After that i bought a parts SB200 just for fun and did that also with a single 7igb tube. Harbach soft-start wired for 120VAC operation 4. ) the power supply will be disconnected. The triode is available in two variants differing in the type of cooling: the GI-7B with a heat sink for forced air cooling and the GI-70B with no heat sink for other Mar 14, 2025 · Please take full precautions, dim bulb tester and so on, assume the pre-amp main board caused the power supply to fail. US $40. The powersupply, including the heater supply from 12 = volt is okay, it doesn't drop down. valtek_2005 (16,118) 100%. So admire the efforts to just build a new board, not to difficult design. A steel bulkhead (. > Hamilton Horta - PY2NI skrev: > > Hi everybody, is there any rule of thumb or whatever to determine the > > minimum > > amount of electrolitic caps should one put in a HV power supply? > > I am building a VHF PA with 1x GI-7B @ 2200V and another for a friend of > > mine with 2xGI-7B, I know that we are usually biased to use as much as > Hamilton Horta - PY2NI skrev: > > Hi everybody, is there any rule of thumb or whatever to determine the > > minimum > > amount of electrolitic caps should one put in a HV power supply? > > I am building a VHF PA with 1x GI-7B @ 2200V and another for a friend of > > mine with 2xGI-7B, I know that we are usually biased to use as much as Sep 12, 2021 · 1. This one went 30 plus. Show all keyboard shortcuts. The tubes GI6b, GI7b, GI7bt, GI70b and GI70bt are all the same GI7b. Title: GI7B GI70B Author: Electronintorg Subject: JA-2003-01-16 Created Date: 12/14/2002 7:52:05 PM Oct 6, 2009 · Got the HV and LV power supply rebuilt. 6v @ 3amp transformer, the plate choke, and by-pass capacitor must be located on the plate. There are many GI-7B ccts about. The amplifier was designed by Gabor Draskovits, HA1YA, who produces similar amplifiers commercially for export. KB0NLY wrote: >I'm using GM3SEK's Triode Board for my 6m amp project using the GI-7B, >i ran into a problem today with the power supply. , coba upload skemanya ! Tercatat Feb 23, 2012 · Yes, I was planning to play more with the GI-7B tubes. Test with 2 ? GI-7B and an external input circuit (ATU) to obtain SWR = 1 on all bands. New. > /*snip*/ > >> GI-7B just a question about what the true limit of plate voltage > is?? > > Increasing the plate Voltage allows a tube/s to produce more RF > power, (once you reach the > current limit of the tube) within Used at full power EME since Dec. Test with minor modifications of the schematic. Heathkit SB200 Mods/SB-200 Modifications. $42. This small HV-supply is actually great for many medium power amplifier. 2 x GI-7B 432 MHz amplifier project: No schematic. They are very reasonable in cost, plentiful, rugged, and designed with horizontal mounting in mind. Used at full power EME since Dec. This project actually started over a year ago. Nov 29, 2019 · To have a true grounded grid requires the negative side of the HV supply to float at -8. Connect +12V to the clear lead, and the power supply ground to chassis ground. Nov 30, 2019 · K4POZ sells a socket for the GI-7B(T). 6 VAC filament transformer and 2 × GI-7B. This is a quick "walk-through" of a Yaesu FL-2100B amplifier that I converted from the old (expensive) 572 tubes, to the very durable (and inexpensive!) Russian GI-7B ceramic triodes. Here below you will find some shots of the various stages of assembly and a short video of the final testand now ladies and gentlemen start your engine!Gi7b homemade amplifier#Gi7b #HF # Mar 6, 2010 · High Power Amplifier GI-7B by GusGus Lhah Trafo Power supply masak ndak punya ground ah yang bener aja yah. sch. Seems to be about the same as the GI-7b that a couple of Ebay sources sell for that or a little more. "Half Kilowatt GI7b Amplifier for 23cm" Nov 4, 2022 · Hello everyone. Heat the tube 30 minutes with a filament voltage of 12. Oct 7, 2013 · Still holding out hope that someone here can help me repair this PP-7B power supply, but I think at the very least I need a way to verify voltage coming out of IC2 (3D-1001) and a way to replace it. If you are mechanically inclined you could probably build your own easily. or Best Offer. I came across another tubeless. It would likely supply significantly more current in ICAS. My effort is no different, and it works. New 12 VDC T/R relay---17ma keying 6. Opens in a new window or tab. Be sure to use a separate cathode choke for the B- and the bifilar choke on the filament leads. Much of the idea comes from Fritz at pa0fri, a mine of info. With this linear you can make 350-400 Watts on SSB. The following describes a few changes in this second conversion. Why not inexpensive GI-7B?only needs add a 6V filament transformer. New quiet cooling Hamilton Horta - PY2NI skrev: > Hi everybody, is there any rule of thumb or whatever to determine the > minimum > amount of electrolitic caps should one put in a HV power supply? > I am building a VHF PA with 1x GI-7B @ 2200V and another for a friend of > mine with 2xGI-7B, I know that we are usually biased to use as much as > possible but I am really eager to know the minimum for these two I'm using GM3SEK's Triode Board for my 6m amp project using the GI-7B, i ran into a problem today with the power supply. shoehorned into the amplifier. I was probably power supply limited, using the power supply out of my FAA single 4CX250B amplifier. All of these amplifiers are in daily service on 6 and 2 meters and trouble free. This has nothing to do with the Disney movies, i decided on Piglet as I consider the amp to be the daughter of my GS35b amplifier that acquired the name 'The Pig', the reasons for that can be found elsewhere on my web site. Röhrensockel für Koaxialöhren vom Typ GI7B und GI6B Handgemacht in Deutschland Geeignet für Gitterbasisschaltung (englisch: grounded grid) Einfache Montage mit M3 Schrauben. Mar 21, 2005 1,390 75 58. The GS-9B is a very similar tube used for signal amplifiers. Here are some comments and pictures. I have built around 25 aVHF amplifiers over the past three years using the Russian triodes, GS-35 and 31B tubes as well as GI-6 and 7B tubes. V12-Feb-2010 AMERITRON AL-811H modifications. The GI-7B tubes have 12. Condition: New New. This cycle happens = in about 3 seconds. Reply. DESCRIPTION A plug is on the end of the black/yellow wire to connect to this header (you can also just see a ferrite bead at the plug end of this wire on the control board picture, #2 at Figure 4). What is the difference between the GI-7B and the GI-7BT triode tubes? Here's a breakdown of the differences between the GI-7B and GI-7BT triode tubes: GI-7B Cooling: Designed for forced air cooling with a heat sink. 100, pretty easy to find). Some modifications are needed to the plate and grid current metering circuits. 6 Meters: 28. Took out all the garbage that was installed. Front view of the completed PA rack assembly, PA above power supply. It was groaning pretty vocally At that time, I was buying Gi-6B's from Vladi, UT5JDS for USD 7 each, so didn't really care if I sacrificed one to science 73 John VK4TJ My power supply is a full wave voltage doubler with 560V AC giving about 1. Has a built-in power supply, RF relay and is wired for 100v mains. Power Meter; Pegelmesser; Attenuatori vari; Valvola Gi 7B Nuova di produzione RUSSA-con dissipatore in alluminio-Allo stesso prezzo BOX VALVOLE, lampade e その7 1296mhz 板金加工に工作機械を必要としない水冷方式gi-7b 1296mhz 300wアンプの製作 その8 1296mhz gi-7bとgs-34を使った1296mhz帯同軸型キャビティの製作 その9 2424mhz 2100mhz cdma基地局用デバイス流用2424mhz ldmos使用100wアンプの実験 Apr 12, 2025 · GI-7B Triode NEW Tube power amplifier QRO HF VHF UHF GI7B. 0 Partly finished conversion with a doubling power supply, a 12. A technical article is under preparation please be patient. 0: 6K7: 58: 1xQB5/1750 - 6 meter Power Amplifier: Over a Kilowatt on Six Meters. com> > To: "Hugh VA3TO" <hduff@cogeco. 9b) The square bar under the lockdown bar attaches to notches cut into the inside wall of the cabinet. May 8, 2025 · The amplifier uses four Motorola MRF150 50 volt TMOS power FETs configured in push-pull/parallel and biased for class AB linear operation. The wattmeter pick up circuit was remounted between the wire coming off the end of the tank coil and the relay (see picture). New power supply board assembly 2. Most switchers have enough adjustment to make up for slight voltage drop across the filament choke and connecting wiring. The goal of this amplifier is to have a 10-160 meter amplifier that would safely achieve 1500 watts output on all bands and fit nicely on the desk at my operating position. or Best Offer Mar 23, 2020 · Power Supply Capacitors and New Filament Transformer. Rear view. 5GHz+! Tom, The SB-230 used a single 8873 (conduction cooled 3CX400A7/8874). I was looking for a cabinet to house a homebrew GI-7B amp that I was moving from Clipperton-L schematic with modifications for GI-7B tubes, grid meter. Of course is this not so much from this tube, but 2 GI-7b can use this supply. 35 to 1. And, as with all of my amplifiers, it has been given a name and this one is Piglet. Perhaps even more affordable and readily available would be like a couple of 811a tubes in grounded-grid running say 200-300 watts PEP. 33 An RF power supply for 144 MHz Mountain Top Electronics, a boutique manufacturer, specializes in handcrafted amplifiers designed for durability and performance. HV power supply and RF deck are in two separate boxes. A high power push-pull 572B amp can use as few as two tubes per side and provide 500 watts. 5 to 30 Mhz RF Amplifier This high range amplifier is very small [SB200 size] Vacuum variable input and output caps as well input and output switching. Information seems to indicate that one GI-7B is equivalent to, or slightly exceeds the performance of a pair of 572B's. Nov 4, 2021 · The GI-7B tube used to be popular for homebrew amps up to a few hundred watts, but I am not sure anymore. Linearity is very good as measured on my trapezoid scope. the 2800 volts or more required for the glass triodes. Features like tuned inputs, AB biasing, SSB delay, and forced-air Figure 6 AA4PG 3/30/2013 [email protected] Page 6 of 14 Power Supply Capacitors and New Filament Transformer The preceding describes the first Dentron conversion. DESCRIPTION On the original Dentron schematic, both were keyed together. Has Kenwood TL-922 HV transformer with Harbach soft-start and new Heathkit SB-220 Harbach replacement power supply board. $37. The blue colour marks the details. Please note, that during the GI-7B conversion, some of the ‘B’ features were removed (to simplify bias, etc). The project started as a retrofit of the Clipperton with GI-7B tubes. com> > Sent: Monday, July 16, 2007 5:14 AM > Subject: Re: [Amps] AL-811H conversion ? > > >> >>>I have the opportunity to aquire an Ameritron AL-811H that >>>needs a new >>> transformer for the HVPS Hello everybody, this post is about my passion for DIY. or Best Offer +$12. 6 volt filaments so a filament transformer has to be somehow. Here is the schematics for the bias control. the can) and would heal after the power was removed. So the power indicated must have been real! There are much more advanced tubes than the GI7b. . If not, my alternative is to go with a new switcher. The preceding describes the first Dentron conversion. I recently bought a used one on-line at a reasonable price. Start with around 30V and adjust up or down to achieve an idle current of about 30 Layout was the next consideration. Install Heathkit SB-220 HV transformer 4. Converted the amp to use a pair of GI-7B tubes. you can have an idea on my youtube channel "Dimitris Bel" YouTube Please check and sent me your comments. The GI7b amplifier in its finished state. I just thouh it would be fun to see what that tube would do on that band. Some variants (GI-70B) may not have a heatsink and are intended for different cooling systems. Chassis should to be make for easy approach to every part of amplifier even if that means bigger case. 8. Estate find turned into a labor of love. 2008. But if you think a bit about sockets, screen voltage supply, high pressure blower - you give up easily. It was hard to catch, but luckily I did. Learn more with GE. The GI (“Generator Impulse”) designated tubes are designed for the very high pulse strength required for RADAR transmitters. Switch mode wont last more than 5 to 7 years. My own power supply and timers etc may be different and the layout of course is always a head scratch but the fundamental RF circuits are all similar. 5. GI-7B Bias Voltage: Due to significant differences between GI-7B tubes (new and surplus), and because plate voltage can increase significantly from full load no load condition with some power supplies, it is difficult to predict exactly what bias voltage to use. The GI-7"b" is available in two variants differing in the type of cooling: the GI-7b with a heat sink for forced air cooling and the GI-70b with no Jan 6, 2018 · MODIFICAÇÃO DO AMPLIFICADOR LINEAR DENTRON GLA-1000 PARA DUAS VÁLVULAS CERÂMICAS GI-7B The GI-7B (GI-70B) microwave triode operates as an oscillator and an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. In Bildern enthaltende Röhren dienen nur zur Anschauung und sind nicht Teil des Artikels!. W Power Amplifier for 50 MHz - The power amplifier 6 meter band tetrode GUB / 4CX W VHF Linear - A W MHz GI7b Linear amplifier. Got to work on the bias supply next and then on to the band switch network. The GI-7B (GI-70B) microwave triode operates as an oscillator and an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. Diode protection on meter & LED meter lamp 7. Here you can download the schematics from the RF part: HF Teil. Just by doing that the amp is putting out 35 watts on 40 meters! Not resonant in it's current condition. I don't currently have a 432 amp, but I do have 50 watts out of my FT-847 so driving the triode would be no problem. Increasing the plate Voltage allows a tube/s to produce more RF power, (once you reach the current limit of the tube) within limits. Top view of the power supply for the two GI-7B cavity amplifiers. To feed the filaments of lamps I chose a power supply switcher 12 will 13v adjustable soft START which to start slowly to protect lamps Then the circuit 'entry is a classic that the same assembly that our friend JH0WJF Here is a small glimpse of mounting input circuit that allows to adapt the impedance for a tranceiver Having finally found a transformer suitable for use in a 2x GI-7B amplifier, I am now ready to start building the power supply. The amp was custom built by Carey/KC5GTT and is one of the more popular ones for 2 meters. thumbnail 2 - 3 x GIB=GI-7B. Their amplifiers, such as the renowned 2-tube 3-500Z and GI-7B models, are built with high-quality components like genuine Penta Laboratories tubes. Given the low power supply voltage, I would look carefully at a single 4CX400. Please supply as much information about the product or service as you can, and follow the instructions on the form. With its 350 Watts plate dissipation this tube is a good choice for producing medium power (300 to 500 Watts). The Zener then needs to be insulated from the chassis, a simple task by using the usual hardware for mounting TO-3 power transistors. I'm willing to do it. That's great info. Air-cooled Russian GI-7B triode replaces the conduction-cooled 8873. It is 2. The conversion seems very straight forward-and the ultimate performance is only limited by the capacity of the amp power At a Dutch rally I once saw an open Heathkit SB-200 HF linear amplifier. 1. $ thumbnail 1 - 3 x GIB=GI-7B SOVIET TRIODE Tube w. GI7B tube datasheet Converted amp schematic diagram W4ZT bias board My power supply is a full wave voltage doubler with 560V AC giving about 1. Feb 26, 1993 · GI-7B Tube Sockets - I build these sockets for the Russian GI-7B. The GI-7b, GI-70b and GI-7bT microwave triode operates as an oscillator or an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. I don't really need an amp for six- I have an 8877 on that band as well as on 2 and 222mhz. NorthStar Administrator. The replacements are NOS, and available in abundance via the internet at reasonable $/watt prices. 6. GI7B / GI-7B HF-VHF-UHF POWER COAXIAL TRIODE TUBES RHOMBUS NOS QTY-2. Top view. GI-7B, GS-35B, GS-31B, GU-43B: GS-31B/GS-35B amplifier that i bought from some HAM guy in Abakan, Hakasiya. I have a 2 KV @1 amp commercial supply. The power supply is quite low for the GI-7b (or 572B) providing about 2100 volts vs. The majority of amateur radio designs using these tubes are based on 3/4 lambda cavities, the famous CT1DMK design being the prime example. For a few $ more, a robust version is available, the GI-7BT designed for tropical climates of high temperature and humidity. 7. It is available with either forced air cooling or other cooling systems. This is the Cadillac socket that provides excellent electrical connection using finger stock in a true plug in socket with lots of air flow around the base of the tube. Brand New. Writing a Review Click the link on the details page to take you to the form to write a new review. 2KV @ 0. Input Power monitoring: The drive power is monitored to shut the PA down in case somebody applies too much power to the input to avoid damage to the FET. After it tests okay, proceed with further tests to find the fault. The triode is available in two variants differing in the type of cooling: the GI-7B with a heat sink for forced air cooling and the GI-70B with no heat sink for other May 8, 2025 · This little gadget is that it allows you to tune up at full peak output power, whilst limiting the average power to a fraction of the peak, thereby protecting the PA from meltdown TS-850S Amplifier Interface An interface for amplifier to TS-850S Modifications to the Ameritron AL-1200 Amplifier Heathkit SB200 Mods/SB-200 Modifications. Re-activation. ca>; <amps@contesting. Hits: 2594 | Votes: 3 | Rating: 5. I am seriously considering building a dedicated single band amp for 160 meters. Aug 23, 2013 · There are various opinions and solutions how to do it, but with a GI-7B it can be relatively simple. Here you can download the schematics from the power supply: Netzteil. The well-known 4CX250B has almost the same dissipation and power range and needs less drive. DESCRIPTION The GI-7B microwave triode operates as an oscillator and an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. The amplifier uses transistors that have been designed for VHF SSB operation. By modifying this amp were minimal changes to the original design and as far as possible minor initial components used. GE Power is a world leader in power generation. A brand-new, unused, unopened, undamaged item in its Mar 14, 2025 · Discussing a " redesign" for a Class A pre power supply to be more efficient is almost comical. Structure: Standard… So far the GI-7B has proved to be a great tube. K4POZ page on retrofit using the GI-7B; W5KG page on retrofit using the GI-7B; WD8DAS page on retrofit using the GI-7B; OZ1BV page on retrofit using the GI-7B The supply voltage is monitored, so in case of a regulator malfunction (overvoltage e. Quiet power switching relay prevents ON/OFF switch failure. I have make some tests with ceramic russian tubes 6S17K-V GS-13 GS-4V and GI-7B. 7b) Power supply board has a soldered wire, instead of a fourth fuse, that seems factory-original. My experience with high power transmitting tubes (IOT-D2100) is; the tube runs cooler and lasts longer at the lowest supply Voltage that the tube can make the required power. Useful links to SB-230 retrofit projects can be found below. 5KV no-load, 2. A DC of 30 to 40 V is sufficient for the tube to draw 500 mA as the grid is connected to the anode. Then supply a HT of about 25 V "high voltage" and set for a current of 400-500 mA. All I have to compare it to is my SB-200, but it compares very well. Heatsink removed, plenty of vent holes all around. New solid state timer for filament warmup delay. Apr 14, 2002 · Current drain for those two supply voltages are pretty low, so this trick works pretty well. May 30, 2024 · - polypropylene capacitors (MKP) in HV for GI-7B output tube - regulated power supply for all stages (for the output stage as well) - automatic bias current control for the output tube with long term stability - switch selector for up to 100W or 40W of power output (with switch position on rear panel) The power supply side with near 2000 Volt. > /*snip*/ > >> GI-7B just a question about what the true limit of plate voltage > is?? > > Increasing the plate Voltage allows a tube/s to produce more RF > power, (once you reach the > current limit of the tube) within Nov 5, 2019 · Hello and 73 are described below my amplifier HF equip three GI7B the project to start by browsing the web. And in my application (RTTY > > mostly), efficiency is the name of the game because you only have 700w > of > > total Pd. 8A (400mA Per tube), key down. Then it would do it again once power was turned back on. The PAs are biased for 100mA plate current each, no drive (idle). N. Solid state 90 second timer for filament warmup 8. I'm using GM3SEK's Triode Board for my 6m amp project using the GI-7B, i ran into a problem today with the power supply. I sold this linear, after a longer usage. Fitting two gi7b tubes into the SB200 doesn't get you much more output, just not enough B+ current available for more. 2500 and couldn’t resist. 6m amplifier with 2x Gi7b by 9A3MR. Here is a summary: 1. A schematic will be added to this page later on. 00 it had 1 bad tube and the power supply had 2 bad filter caps and some blown diodes in the doubler. However, the more I worked on it the more changes I made. May 8, 2025 · A 2 meter power amplifier G4DCV's 144MHz amplifier with a pair of GI-7b Russian triodes. This also damaged another capacitor in the string, so I decided to replace them all. Does anyone have a schematic of the power supply and any idea what the supply voltages and currents are? Thanks in advance. The current rainbow connector coming out of the power supply looks like this. The first design. In both cases power output was higher than original tubes. Aug 30, 2005 Take the GI-7B for instance 2pcs GS-9B Same Date microvave version GI-7B NEW Tube power QRO HF VHF UHF GS9B. Second of all, performance. Regards Dimitrios The most common tube used for replacing the 8873 in this amplifier is the Russian GI-7B, a VHF power tube originally used in Russian RADARS. New T/R relay with 12VDC @17 ma keying. It is tight but will fit. ctrl + g :. 4. I plan to use a voltage tripler to wind up at around 1900 volts. 5GHz+! I have a 400+ watt 2 Meter GI-7B Amplifier using a Russian GI-7B Triode tube working 100% for sale. During a visit to an HAM exchange exhibition (Radiantistica Expo) I came up with the idea of building an amplifier using the mythical Russian tube Gi7b. It sounds like 4 Gi-7b's would run forever. There are other tubes as well that would be interesting to try such as the Russian GI-7B and variations of that tube. Partly finished conversion with a doubling power supply, a 12. I have a Krell KSP-7B preamplifier, but we lost the external power supply when we moved. The power output limiting factor mostly is the power transformer. 8b) Screw heads are visible on the inside of cabinet, not on the outside. " 550 Watts: 30. Find the GIFs, Clips, and Stickers that make your conversations more positive, more expressive, and more you. 1996. 5kV maximum output before significant compression appears to be about 560W PEP - well within the ratings of the valve. GI-7B with a smaller cooler for the anode. Many thanks. Builder reports: "Compared to building HF and low VHF amps, this was very difficult. The open amplifier seemed suitable for modification to accommodate the Russian valves GU-43B, GS-35B or GI-7B to get more output. Sep 20, 2010 · Pretty much in line with the various US web pages describing conversions. A 144 MHz GI7B Power Amplifier This construction article appeared in 1987 in Radiotechnika magazine (Hungary). Gidday all. I purchased a Clipperton QRO amplifier that was a. Key specifications include a maximum height of 110. Under the RF chassis. Power output will be about the same as the pair of 572's I have not done any of these conversions yet, but I am in the process of converting an MLA-2500 to a pair of GI-7b's and a Henry 2K-4 to a GI-35b. Since I very rarely operate SSB, a pair would probably do the job. The large grid band is clearly visible below the purple ceramic insulator. The GI-7B microwave triode operates as an oscillator and an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. I came across another tubeless 2500 and couldn’t resist. …. Here are some comments and pictures. According to his manual, i sent him an email as well waiting for a reply, for 2500v i should use 10 1M Ohm resistors in series from the B+ line, on the end of that string of resistors there is also two 100k 1W resistors to chassis ground. New Harbach soft start wired for 120VAC--NOTE: GI7B filaments only draw 2 amps @12. DESCRIPTION. According to his >manual, i sent him an email as well waiting for a reply, for 2500v i >should use 10 1M Ohm resistors in series from the B+ line, on the end >of that string of resistors there is also two 100k 1W resistors to >chassis ground. My GS-31 PA can deliver about 600W CW output. Well I could not find a 8875 that I could afford so I sold the good tube and bought 4 GI-7B tubes and all the parts I needed for the conversion plus a New Kenwood TM-271. 2 V (the bias Zener diode voltage). Power multiplication factors of 10x to 14x can be expected with 40-60w drive. High voltage section. RF deck consist input circuit, tubes and output circuit. and a small muffin fan running at reduced voltage. 028” thick) was fabricated and placed between the power supply components and RF compartment to better isolate the two functions. (c) DJ9KW, 25. AEA LA-30 HF Linear Amplifier, operating manual & schematic………………………. The GI-7B/GI-70BT microwave triode can operate as an oscillator or amplifier in continuous or pulsed modes in the centimeter and decimeter wavelength ranges. 00. Feb 24, 2018 · audio amp with GI7B GI-7B Hi. GI-7B Russian NEW Tube power amplifier QRO HF VHF UHF GI7B. At a Dutch rally I once saw an open Heathkit SB-200 HF linear amplifier. The bias diode checks good so that is a plus. GIPHY is the platform that animates your world. Some tubes. Aug 23, 2013 · Partly finished conversion with a doubling power supply, a 12. The triode is available in two variants differing in the type of cooling: the GI-7B with a heat sink for forced air cooling and the GI-70B with no heat sink Neutralization of GI-7b / GI-7bT 23cm Amplifiers It is well known that 23cm PAs using Russian GI7b / GI7bt tubes suffer from thermal drift and can oscillate under certain conditions. The catch is that I cannot remember how to size the diodes for PIV. You may possibly build a HF amplifier with the information in this article. In Bildern enthaltende Röhren dienen nur zur Anschauung und sind nicht Teil des Artikels! Art & Craft Supplies; Stamps; Entertainment Memorabilia; Music; GS-9B microvave version GI-7B NEW Tube power QRO HF VHF UHF GS9B. Wire the RF paths from the input and output RF jacks, the power sensor output, and the GI7B input coax as shown in the schematic. All enclosed in a beautiful blue powered coated case. This design is also suitable for Russian triodes such as GI-7B («fig), GS-31B and GS-35B(GS-7B) TB3/750 TRIODE . The outside look: The cavity and tube: A very good reproduction of this design by DL4MEA "GI7b 1296MHz 500W-Amplifier" Also working with this or similar design are: PA3CSG, JA9BOH, DL4MEA, S57RA, RW3BP. Hsu >----- Original Message ----- > From: "Tom W8JI" <w8ji@w8ji. This and size limits me to the 225W output, but at 2. I bought my MLA-2500 at a local swapmeet for $85. Free exponent calculator - step-by-step solutions to help simplify the given exponential expression. At the price they must be the gift of the century! And they are rated to 2. Please follow the instructions on the form as you write your review. g. New complete Harbach power supply rebuild includes electrolytics, rectifiers, metering and bleeder resistors. It's not a difficult conversion, and I've included the schematics at the end, of the tuned input and other mods to make this work. 05. The problem is = that when the power comes up, it goes to about 200 watt, it stay there = for about two at three seconds, then the power drop down to about 20 = watt, and then it comes up to about 200 watt again. 5mm, maximum weight of 330g, indirect oxide cathode, ceramic envelope, and operating temperatures from -60 to 100 Aug 30, 2005 · I will post pics of the High Voltage power supply later. I'm curious to see what kind of power gain I get out of the small 350-Watt russky ceramic triodes. Power supply. from I use switchers for the filament of the GS-35B and GI-7B which both have indirectly heated cathodes with no ill effects at all. Idea was to make cheap, easy to built amplifier. G4DCV's 144MHz amplifier with a pair of GI-7b Russian triodes: G8ACE Medium Power Amplifiers for 24Ghz: BANDIT 1000A, IK0IXI GS35b Power Supply,PA3EXV: GS35 Nov 30, 2019 · K4POZ sells a socket for the GI-7B(T). This model, first marketed around 1965, still features in many amateur stations. PS have soft start circuit, HV transformer, rectifiers and filter condensers. On the right side 2 resistors in parallel is inserted into the main supply and short circuited by the relay after 2 sec. Scored a GI-6B for 25 bucks on Ebay. 6VAC each, so no need for 240 operation. Just a little time. I see cites yu1aw without which this project. The tube was temporary mounted on a base of a defect 3-500Z for eventually testing in my FRI750 PA. It's a doubler with huge capacitors (8 x 1900 uf) and small transformer. My transformer provides 650 Volts at around 1 amp. Navigate to a group Oct 24, 2016 · About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Aug 2, 2013 · This is my first home-brew amplifierI caught the bug after retrofitting a GI-7B into my GLA-1000 so I wanted to try building one from scratch. ppah rzupvwwn akakcuq szc eikz wfzz hwnq xyvj wuuognwi ikwdwin