This SDR Uses A Tube
The build was an experiment to see if a tube receiver could be stable enough to receive digital shortwave radio broadcasts. To avoid AC line hum, the radio is battery operated and while the original uses an EL95 tube, [Mirko] used an EF80.
This SDR Uses A Tube
Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.
Special Thin wall SDR 3/4" Type II PVC ( O.D. = 1.05" and I.D. = 3/4" ) used in residential water filter tanks. ( sold by the foot ) is used in most water system made after 1998 and many before that date also. Was also used in some Fleck and Erie Valves. Now most Valves use the 1.05" size tube, which is equal to the outer diameter of 3/4" PVC pipe.NOTE: We will only ship pipe in 36 inch lengths or shorter. If you need a long piece, we will ship it in sections, and you would need to purchase PVC slip x slip coupler ( from local hardware store ) to connect the pieces together. We recommend you order and use the larger 1.05" O.D. distributor ( our MD1236 ) when possible, which will allow you to use 3/4" PVC pipe for your tube. Common Schedule 40 PVC ( with thicker outer wall ) can be used instead of this thin wall SDR Type II pipe. And both 3/4" PVC pipes ( SDR or Schedule 40 ) should be available locally from larger hardware / plumbing supply outlets.
Methods: Two different stainless steel endodontic instruments (ISO 20: Hedstrom files, K-files; VDW, Munich, Germany) were cut at the diameter of 0.4 mm. These fragments were fixed in a vise leaving a free end of 1 or 2 mm. Cyanoacrylate (Instant Fix; Henry Schein Dental, Melville, NY), dual-curing Rebilda DC (VOCO, Cuxhaven, Germany), and light-curing SureFil SDR (Dentsply, York, PA) were placed into microtubes (N'Durance Syringe Tips; Septodont, Saint-Maur, France) and shifted over the instruments (n = 20 in each group). After polymerization, pull-out tests were performed with a constant speed of 2 mm/min; failure load was measured digitally. Data were analyzed using the Kruskal-Wallis test followed by the Dunn test for pairwise comparison.
Conclusions: Within the limitations of this study, the use of light-curing composite inside of the microtube was superior compared with the use of cyanoacrylate or chemically cured composite, which are being used presently.
CRERW: Cold Rolled Electric Resistance Welded. This is themost common and least expensive of the three we will talk about here. This tubeis rolled into shape from a flat plate of steel and then welded creating avisible seam. This tube type is used here at SDR for connector tubes andnon-critical bracing such as the V-bars in the roof area, dash bar, andthe 1 inch bracing in the windshield and corner gussets. If your cage is builtfrom this material it should be .120 wall thickness to maintain the samestrength as .095 wall D.O.M. tubing wich we will talk about next. Also criticalto strength when making a cage from this material is the seam placementduring bending. Having the seam aligned with the inner or outer surface of thebend can lead to failure by causing the seam to rupture or split during animpact.
D.O.M.: DOM stands for Drawn Over Mandrel Steel. DOM Tubing is much moreexpensive and much stronger then CRERW. This DOM type of tube is oftenincorrectly referred to as seamless tubing. While it appears to beseamless because of its flash removal after the welding process it is alsorolled and welded. This type of tube is most commonly used for structuralproducts for its consistent ID and OD tolerances. DOM is also a very easymaterial to work with as it bends well and can be MIG welded with no heattreating or stress relieving needed. This is the material we use for all of themain structure of every SDR cage we build.
The only problem I had was too much conversion gain. Even with a relatively short antenna, and literally starving the tube for voltage, the signal output levels were high enough that I had to crank back the gain of the RTL SDR and/or use padding on the input of the RTL-SDR.
Recently I built a somewhat similar upconverter using ech81 heptode-triode. Triode works as Meissner (aka Armstrong for US people) oscillator (LO) while heptode works as mixer and RF amp. G3 tied to Triode grid, G1 is RF input. Vacuum tube upconverters have massive signal levels so they cannot really be plugged in directly. It peaks my RTL-SDR input even when beeing couple meters apart(small antenna provided with generic RTL-SDR). Around 200V anode, G2+G4 at around 85V. Triode anode at around 60V. Cathode at ground level. LO at around 11MHz, bringing some HF signals into RTL-SDR low-end usable range.
CPVC pipe for plumbing systems is manufactured by extrusion in sizes " through 2" copper tube size (CTS) dimensions. The CTS plumbing products are made to copper tube outside diameter dimensions, in accordance with ASTM D2846 specifications, and have an SDR 11 wall thickness. The pressure ratings of the CTS SDR 11 systems are 400 psi (pounds per square inch) at 73 F and 100 psi at 180F. CPVC plumbing pipe is sold in both straight lengths and (in small diameters) coils.
CPVC pipe and fittings are produced by many manufacturers, and are available in Schedule 40 and Schedule 80 dimensions, as well as CPVC tubing which is suitable for potable hot and cold water distribution. The tubing is based on copper tube sizes (OD) and IPS pipe (OD), with SDR 11 wall thicknesses.
PP-R is a high-temperature plastic pressure piping system first used for plumbing and hydronic heating in the 1980s in Europe and introduced to North America in the 2000s. PP-R was first used for various industrial applications in the 1970s in Europe, and the first reported usage of PP-R in North America for industrial uses was in 1986.
The relative roughness of a pipe is its roughness divided by its internal diameter or e/D, and this value is used in the calculation of the pipe friction factor, which is then used in the Darcy-Weisbach equation to calculate the friction loss in a pipe for a flowing fluid.
SDR pipes and associated fittings are used for various applications like agriculture, irrigation, water supply, industrial process lines, swimming pools, and firefighting mains. SDR pipes often provide stormwater and drainage applications. SDR-17 polyethelene pipes are suitable for gravity sewage applications, while thinner tubes like SDR 20 are ideal for shorter and smaller diameter applications.
Wastewater lines can be a real headache. If they're not somewhat flexible at the joints, they can have issues when cold weather and frost heaves cause the pipes to displace. If that happens, you can end up with some serious problems with sewer leakage and potential contamination of ground and surface water supplies. Fortunately, there's a better option than standard PVC; SDR35 PVC sewer pipe. Here's a bit more on this flexible, solid-sealing option and how it can benefit your water utility in the field.
Once the pipe is lubricated, align the bell and spigot, then insert the spigot into the bell until the gasket is contacted uniformly. The insertion depth is marked on the outside by a stop mark or assembly stripe to help you reach the proper depth. Do not insert the pipe past this mark, as doing so could void your manufacturer's warranty.
If you've ever shopped for PEX tube you probably know there are three main types. These are PEX A, PEX B and PEX C. In hindsight, that's an unfortunate naming scheme, because it makes it sound like these are grades and implies that one is better or worse than the other. They are actually types of manufacturing processes to achieve a finished product. Anyone buying or working with PEX should know the differences so as to know how to select the proper tubing.
PEX tubing has a lot of advantages in plumbing applications, but buyers should know the differences between the three types. While all three meet applicable standards, cost, and flexibility, the installation methods do vary. Buyers should remember this when deciding which type of PEX to use.
IMPORTANT- READ THESE TERMS CAREFULLY BEFORE ENTERING THIS ASTM PRODUCT. By purchasing a subscription and clicking through this agreement, you are entering into a contract, and acknowledge that you have read this License Agreement, that you understand it and agree to be bound by its terms. If you do not agree to the terms of this License Agreement, promptly exit this page without entering the ASTM Product.
(ii) Single-Site:one geographic location or to multiple sites within one city that are part of a single organization unit administered centrally; for example, different campuses of the same university within the same city administered centrally.
B. Authorized Users:any individual who has subscribed to this Product; if a Site License, also includes registered students, faculty or staff member, or employee of the Licensee, at the Single or Multiple Site.
3. Limited License.ASTM grants Licensee a limited, revocable, nonexclusive, non-transferable license to access, by means of one or more authorized IP addresses, and according to the terms of this Agreement, to make the uses permitted and described below, each ASTM Product to which Licensee has subscribed.
(ii) An Authorized User may not make this Product, or Documents, available to anyone other than another Authorized User, whether by Internet link, or by permitting access through his or her terminal or computer; or by other similar or dissimilar means or arrangements.
(iii) Specifically, no one is authorized to transmit, copy, or distribute any Document in any manner or for any purpose except as described in Section 3 of this License, without ASTM's prior express written permission. In particular, except as described in Section 3, no one may, without the prior express written permission of ASTM: (a) distribute or forward a copy (electronic or otherwise) of any article, file, or material obtained from any ASTM Product or Document; (b) reproduce or photocopy any standard, article, file, or material from any ASTM Product; (c) alter, modify, adapt, or translate any standard, article, file, or material obtained from any ASTM Product; (d) include any standard, article, file, or material obtained from any ASTM Product or Document in other works or otherwise create any derivative work based on any materials obtained from any ASTM Product or Document; (e) impose any charge for a copy (electronic or otherwise) of any standard,article, file, or material obtained from any ASTM Product or Document, except for normal printing/copying costs where such reproduction is authorized under Section 3; or (f) systematically download, archive, or centrally store substantial portions of standards, articles, files, or material obtained from any ASTM Product or Document. Inclusion of print or electronic copies in coursepacks or electronic reserves, or for distance learning use, is not authorized by this License and is prohibited without ASTM's prior written permission.