开云体育

Here's an update on the SVHFS 2025 Conference; Deadline for papers has been extended to March 17 Registration is open; details are in the attached file. Thanks, Robin Midgett K4IDC

Over the years I've collected parts to build an amplifier. Life got in the way during most those years but now I find myself with the time and ambition to build an amplifier for my boatanchors. As far as bottles are concerned I have a bunch of 813s a 3-400Z,. couple of 4-400s and of course the usual 811s, 807s, 6146s........Got plenty of iron for a power supply up to 3kv. Need some direction as to which way to go. I operate 40 thru 10. Have a soft spot for AM. (yes I'm old) but do CW and SSB. Finishing up a 350 watt modulator. OR should I forget all this stuff sell it and buy an amplifier. don

Hello, Can the vintage or date of manufacture be determined from the serial number on an Ameritron AL-82? Thanks and 73, Garry - K4OR

This one is from 1965: https://www.eham.net/reviews/view-product?id=12175 A ham I know says his ant relay is stuck, its an open frame relay he says. Probably no parts for this one around anymore? -- Steve Hearns [ KA2PTE ] Technotronic Dimensions, VT [USA] WWW.TECHNOTRONIC-DIMENSIONS.COM E-Mail: Steve@...

The timeline for submission of papers and presentations has been extended to March 17th.

Gonna try and detox an ACOM 1500 amp previously owned by a smoker ham, anyone ever have to remove the niccotine film before maybe with chemicals? Contact cleaner wont take it off, alcohol on a rag seems to dissolve it, so I may try that with small toothbrushes to get into the tight spots. I read someone once hung a smoker contaminated ham rigg from a wire in their garage and put cardboard under it, and soaked it inside and out with WD40, let it penetrate overnight and said it yielded good results. Not sure about that tho. -- Steve Hearns [ KA2PTE ] Technotronic Dimensions, VT [USA] WWW.TECHNOTRONIC-DIMENSIONS.COM E-Mail: Steve@...

Somebody who previously owned my Commander HF-2500 replaced the carbon resistors in the plate parasitic chokes with a different type of resistor. This worked fine on low frequencies 160M, 80M, and 40M. When I used the amplifier on 10M, it became very unstable, most likely with a parasitic oscillation and caused the plate blocking capacitor to explode and catch on fire. The main fuses blew, as well as the one on the board that contains the bias and control circuitry. After replacing these fuses and installing carbon resistors in the parasitic suppressors, I found that the amplifier would no longer work on 80M. Eventually, I discovered some discolored places on the plate RF choke where it had evidently arced through its insulation causing the needed 10M high impedance to shift. The choke was replaced with one I had from another Commander HF-2500 that has been a source of spare parts. While trying to do this, the windings (there's more than one - rather complex winding - some over the top of others) became loose, and I unsuccessfully spent several hours trying to get the windings back like they were and tight on the form they were wound on. Even though not satisfied with the replacement choke with loose and sloppy windings, I tried the amplifier on all the usual bands starting at 160M and up to 10M. It seems to work fine up through 15M, but the 10M band doesn't tune properly - most likely because the plate choke was still a problem. Does anybody have an original Commander HF-2500 plate choke that they would like to sell or know where I might find one? Another possibility is to substitute a different plate choke that works well in another amplifier with similar plate parameters. Probably the big challenge in using a different choke would be to mechanically fit it into the rather crowded place in the Commander. Another possibility would be to add a second plate RF choke with a high impedance on 10M in series with the other choke, but this still might be problematical due to the tendency of the big choke to break down as before. Suggestions, especially from anyone who has successfully used a different choke in the Commander, would be very much appreciated. 73, Riki K7NJ

Hi All, I have a DTR-2000L that I'm trying to bring back to life. It's the same one that I asked about last year. What I'd like is IF someone that has one of these amps, that's working, would you be willing to take some pics of the coil and cap section of the tank circuit so I can determine what I need to do to return it to stock. The tank coils have been soldered ALL OVER THE PLACE. All the leads going back to the band switch have been moved and I'm sure some genius tried to convert it to 11 meters. BTW, it DOES appear that is had a NEW socket installed in it and it's marked as such. I won't be convinced on that until I pull it apart and verify the ground connections at the socket. Anyway, if someone could be of some help, I would appreciate it Thanks!!! -- Kim Herron W8ZV w8zv@...

This is a real long shot. I have an old Commander HF-2500 which I love very much. It is Serial Number 186 and it conforms with the printed manual and schematic of June 1990. However, there is no diagram or separate drawing of the Meter Circuit Detail, as published in the later versions of the manual that one finds online. For instance the circuit published 6/16/95. The 1990 Meter Circuit Board does not conform to the later published diagram. Therefore, I am hoping that someone may have been here before me and has the the information that I'm seeking. That is, I'm looking for the diagram of the meter board and the wire colour code and description of the 12 connection points on the board. In particular, points 1 to 8 which relate to grid meter and plate/HV metering and the selector switch. I The Meter board is hard to get to, so I cut mine out to install meter dial LEDs and I extended the wires, so that it could be mre easily removed and serviced. I would dearly like to compare my board to a drawing of the correct era. Any help appreciated. 73 and thanks, Alek VK6APK.

Hello Do you have any recent experience of buying a generator of this type. Please send me references of such a product. Thank you -- F1AMM Fran?ois

? Southeastern VHF Society 2025 Conference Announcement & Call For Papers Quality Inn, 3095 Wilma Rudolph Blvd, Clarksville, TN 37040 April 4th and 5th, 2025 Papers and presentations are solicited on both the technical and operational aspects of VHF, UHF and Microwave weak signal amateur radio. Somesuggested areas of interest are: ? Transmitters, Receivers, Transverters ? RF Power Amplifiers, RF Low Noise Preamplifiers ? Antennas ? Construction Projects ? Test Equipment and Station Accessories ? Station Design and Construction ? Contesting, Roving, DX-peditions ? EME, Propagation (Sporadic E, Meteor Scatter, Troposphere Ducting, etc.) ? Digital Modes, Digital Signal Processing (DSP), Software Defined Radio ? (SDR) Amateur Satellites, Amateur Television In general papers and presentations on non-weak signal related topics such as FM repeaters and packet will not be accepted but exceptions may be made if the topic is related to weak signal. For example, a paper or presentation on the use of FM simplex in contests or on the use of APRS to track rovers during contests would be considered. Formats: All submissions for publication in the proceedings should be in Microsoft Word (.doc or .docx) formats. Submissions for presentation at the conference should be in Microsoft PowerPoint (.ppt or .pptx) format and delivered at the conference on a USB memory stick. Please understand that your PowerPoint Slide presentation will not be accepted to be published in the proceedings; only meaningful text will be published in the proceedings, not slides that need description for understanding. Paper: Size should be 81?2 x 11-inches. Margins: Top and sides should be 0.75 inches; bottom must be 1 inch. Font: You may choose your font, however, try and use standard fonts. The font should be clean and easy to read 12 pt. Layout: Either a one or two-column format. Page numbers: Do not include page numbers. Headers/Footers: Do not include Headers and/or Footers. Drawings: Drawings should be embedded in the files. Place them where you’d like them to appear. Photos: Color or black-and-white digital images if utilized should be embedded in text files. Place them where you’d like them to appear. Printing: We print what we receive. We do not copy edit (but will correct something if we notice it – or if you notice it and let us know). We try to make all papers somewhat uniform, but we do not rework each article. Page numbers are added as we prepare the files for our printer. The deadline for the submission of papers and presentations is February 15, 2025. Please indicate when you submit your paper or presentation if you plan to attend the conference and present your paper in person or if you are submitting solely for publication. Papers and presentations are being handled by Mike Stipick, KC4RI, and should be sent to: KCRI@.... Mike may be contacted at the same email address if you have any questions.

The former employees of All Electronics have formed a new electronic surplus store called Aretronics: https://aretronics.com/

These are now as rare as hen's teeth, so I thought that I'd flag it to the list in case anybody is interested. I have no connection with the seller. See eBay Item No. 116441758244 73s Tracey G5VU

Years ago Gary made a relay-driven protector when it was seen that a large RF signal could damage the circuitry of the transceiver’s RX2 port. It turned out to be an excellent RF amplifier keying driver as the high quality of the driver relay provided a worthwhile isolation. There are a number of available products these days, I hear. Like I.C.E. Products, the KD9SV stamp is to investigate. Hal W4HBM

Happy New Year, I have a fully assembled, tested, but never used Heathkit Shop power supply upgrade board for Drake amps for sale. Price is $125.00 plus shipping from 23418. Details and pictures are available on request. 73, Garry - K4OR k4or@...

I'd like to acquire a 10 - 50 watt linear power amp to use with a 50 MHz. beacon transmitter. Input must be in the 10-18dBm range. Kit or assembled or "needs repair" is fine. Suggestions? Thanks, Robin K4IDC