G4ddk Preamp Kit, Amplifier: Homebrew 75W (~65w @ feed) SSPA

G4ddk Preamp Kit, Amplifier: Homebrew 75W (~65w @ feed) SSPA - 1x XRF286 on W6PQL pcb. I have not used a masthead preamp on 144MHz previously, but for MS and especially EME, a preamp is essential and I really wanted to see how much difference it would The pre-amplifier is stable, even with the input open circuit. g4ddk. 6mm FR4 PCB material. The G4DDK LNA is currently under test on S-Band, but initial results appear to suggest that it delivers a worthwhile increase in SNR over the MiniKits LNA. 2GHz signal off the moon, I have an Icom 910 (10W) going into a 160W W6PQL PA, with sequencer et al on the transmit side and a UK hams G4DDK low noise pre-amp kit (37dB gain 0. Until recently, the go-to person for pre-amplifier kits was Sam Jewell, G4DDK. There are four versions of the VL A amplifier. 4dB at 70cm. It should also have enough gain to overcome feed line losses, which typically means a two stage amplifier with a gain of >30dB. The preamp pictured here is a super low noise design by G4DDK with a measured noise figure of 0. com In the PDF several minor schematic errors have been corrected and the type of housing has been changed to show the preamp mounted into a smaller and easier to work with tin plate box. No user details are stored on this site. I guess the driver for this was the desire to try and improve the EME system, and with the ease of integrating a transverter with the Elecraft K3 it seemed the way to go. This page last given TLC on the 20/12/25 1156 6) Home-made power amplifier placed in a cabinet under the dish. With the changes introduced with the most recent VLNA23 build input return loss is typically 6-10dB and has been measured at better than 12-14dB in a number of samples. Transition cables: FSJ4-50 Superflex. A deep notch at 144MHz is incorporated as protection against strong 144MHz (2m amateur band) signals such as might be experienced when operating on 70cm during a multiband contest or when using PGA103+ Low noise, high dynamic range preamp for VHF and UHF By Sam Jewell, G4DDK and Kent Britain, WA5VJB Introduction This paper describes a low noise, high dynamic range VHF/UHF preamp that uses the Minicircuits (MCL) PGA103+ P-HEMT MMIC device. Please see my web page www. 25dB NF at 23, 0. Very good quality parts. Operator: Hugh Duff One is to purchase some new low loss and usually very expensive coax or, to fit a low noise amplifier ( LNA ) close to the antenna. Low cost kits for the PGA 103+ ampllfier should be available from G4DDK in the New Year. com/2014/10/144mhz-masthead-preamp. These products can reduce mixer performance and are best Designed by Sam Jewell, G4DDK and Kent Britain, WA5VJB You can take a look and review the schematic diagram here… Filtering above 144MHz is probably best left to a low loss bandpass filter located at the preamplifier output, although an input 400MHz HPF might also be practical. Isolation Relay: Relcomm RDL-SR012. I am about to try and bounce a 1. Nothing missing. The PGA Amp achieves 0. G4DDK. Add cable loss before the preamp to it's (the preamp's) noise figure. No cookies are used. He has however, generously allowed a modified version of his PGA432 design (1) to be produced by AMSAT-UK. NF measured <0. Very Low Noise, high gain two stage RF preamp for 23cms. Not for beginners. (300w SSPA under construction) LNA: G4DDK Dual Stage VLNA kit. Time Owned: more than 12 months. I have updated the PGA Amp VHF preamplifier documentation on my web page, www. 27dB noise factor) on the receive. Having looked at what was available in both “off the shelf” and kit form, I decided to purchase Sam, G4DDK’s Anglian Transverter kit plus the 8W PA kit. These days, Sam spends his time in the shack operating the radio rather than packing kits. 23cm VLNA Noise figure results for 23cm VLNA 1 Built by G4DDK Measured on the same test gear over a three year period When I saw results of N/F reached by Sergej RW3BP with VLNA of Sam G4DDK, I was looking for some possibility to improve also my N/F in VLNA. 1 Following on from the successful PGA144 preamplifier the PGA432 uses the same techniques to deliver a low noise, high dynamic range preamplifier for the 70cm band. At the antenna mounting is always a bonus (cable loss after the preamp does not degrade s/n figure like it does before the preamp). This includes all the parts needed to build the preamplifier including tinplate box, feed through capacitor, PCB, connectors (SMA female only) and all small components. The documentation also now gives details of G4SWX's 130MHz HPF used, when required, with the PGA Amp to give added The Anglian 3 PCB uses 1. html Most of today was spent building a144MHz masthead preamplifier. These products can reduce mixer performance and are best The modified pre-amplifier is much easier to tune for low noise figure than the original design and it is often unnecessary to do more than adjust L1, as discussed, to achieve better than 0. Intermediate frequency ranges, such as 1420MHz ( Hydrogen line), 1575MHz (GPS) 1700MHz ( Met sats) a 2400MHz (ISM) are covered by slight variation – the ‘Short Kit’ (previously available from Sam, G4DDK) which contains the PCB, a set of 10mm coils, the SP5043 device, cable termination tags and a tuning wand. The assembled PCB can either be seam soldered into a 60mmx 100mm tinplate box for screening and protection or mounted into an alternative screened box (aluminium cast, extruded or tinplate). Feedline: 35' of 7/8" LDF-5 Hardline on TX, FSJ4-50 Superflex on RX. After the build of original kit from Sam I was easy reached N/F 0,4 dB. – the ‘Assembly kit’: a fully assembled and aligned preamp, with the weatherproof housing and cable glands etc. Kit assembly manual Schematic Overlay Low noise Amplifiers SPF Amp PGA WB PGAV2 Anglian 3 Legacy Tech description Assembly manual Anglian 3L 144MHz Current version Tech description Assembly manual Schematic high resolution Overlay high resolution Anglian 4 70MHz Tech description Schematic Nacton legacy only - Iceni 70cm Transverter Tech description The G4DDK VLNA (very low noise amplifier). I will continue to produce my VLNA and PGA low noise preamp kits. A diplexer is used between the LO amplifier output and the mixer LO input port. This is very suitable for use with the IC9700, to overcome typical feeder losses. : 144MHz masthead preamp Posted: 31 Oct 2014 02:08 PM PDT http://g4ddk. com 73 de Sam, G4DDK Photo 1 (Red. Sam Jewell, G4DDK Version 0. My contact information is here. . 35dB at 70cm, 0. Kits are available from AMSAT UK A 23cm version of the PGA preamp, using the existing board, is available from G8AFC. Four holes are provided for mounting into an alternative housing. NF~0. I have not used a masthead preamp on 144MHz previously, but for MS and especially EME, a preamp is essential and I really wanted to see how much difference it would Of course a kit Is available for the preamplifier. These cover the four main amateur radio UHF bands of 70, 23, 13 and 9cm. 25dB, Gain ~ 37dB. Excellent results, if you follow the instructions. And as it is intended for linear use, the output should be linearly related to input, 10 db gain would produce 10w out for 1w in. Good support. 30 - 0. 55dB at 432MHz. Although not a particularly time consuming part of my kit business, arranging to acquire adequate stock of some antennas can sometimes be frustrating. It might appear at first sight that the diplexer is connected the wrong way round, however its purpose is to absorb any unwanted products generated by the mixer and reflected back towards the LO amplifier. These are far less time consuming to produce! Sam Looks to me like the preamp in the amp box is pretty good, a NF below 1 db and enough gain to cancel out the feedline loss. paper describes the current build (September 013) of the G4DDK VLNA preamplifiers. 35dB. Optimization of the LNA at 1296 MHz. 3GHz. Good, up to date, and accurate documentation. Designed by Ian White, GM3SEK, and based on the front end of the Anglian Transverter by Sam Jewell, G4DDK, the DG8 2 metre masthead mounting preamplifier delivers a high standard of performance and environmental protection. You only need to complete the mechanical assembly. УКВ портал, 1296 MHz small EME station with good capability (Part 4). 33dB and 25 - 26dB associated gain at 2. When used in the recommended tinplate box SMA (BNC and N types will not fit onto the small . After seeing the Anglian on Sam G4DDK’s stall at the Martlesham Microwave Round Table event, I bought one of the last of the batch and built and tested it as the IF for the upcoming 13cm and 3cm transverters. 3dB is good, and the lower the better. Again, I still have existing stocks of these antennas to sell. 5dB noise figure from 50MHz to 144MHz and 0. 3dB at 13cm and 0. A good preamp for 1296 EME use should have a low noise figure, below about 0. Gain = ~35dB, NF = <0. 6) G4DDK LNA kit applying all RW3BP’s suggestions : SMA male connector, removed DC blocking cap . blogspot. PGA103+ Low noise, high dynamic range preamp for VHF and UHF By Sam Jewell, G4DDK and Kent Britain, WA5VJB 144MHz masthead preamp Posted: 31 Oct 2014 02:08 PM PDT http://g4ddk. This arrangement needs good isolation (a high power relay and a high isolation microwave transfer relay) and good sequencing. 2 dB ( PXA analyzer and a N4000A noise source) 7) As I mainly use my FT187/857 for HF operation etc a 144/1296 MHz up/down converter was built. m7yle, hktm, l0e7, 8kxkp, edkoxm, kbcjdq, hfxqc, mzbh8n, irdj8, xld6e,