Differences

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--- radio:projects [2019-10-19 21:08] – Removed GB3ED Speculation Axiom
+++ radio:projects [2022-02-09 02:18] (current) – river
@@ Line 3: / Line 3: @@
 There are a number of projects in the pipeline relating to amateur radio; these will be updated as they progress.
-===== Lab HF access =====
+===== Lab Radios =====
-Antennas tested thus far:
+The lab currently has the following radios:
+  * Icom IC-761. HF Transceiver. Modified for use with external power supply as internal broke.
+  * Yaesu FT-757GX (HF)
+  * Yaesu 7900R/E (V/UHF) (Loan from Ben C.)
-  * TBD. Now we have a radio we can start looking at what Summerhall will let us install and what works best. Inv-V looking like the best option currently. It may be worth making a fan-IV to minimise matching losses.
+==== Amplifiers ====
-Coax drop options:
+There is a 2M Linear amplifier, "The Polar Electronic Developments EDL144" donated by Colin. Notes on it copied from his email follow.
-  * TK is trying to arrange free cabling
+https://worldradiohistory.com/hd2/IDX-UK/Amateur-SW/Archive-Short-Wave-Magazine-UK-IDX/IDX/70s/SWM-1977-02-IDX-20.pdf
-  * Paracord dropped in conduit ready for cables
-Rig:
+It has a cool old power valve inside - http://www.r-type.org/exhib/aag0119.htm I think.
-  * William W has donated a Yaesu 857D.
+I found details, and circuit diagram here: https://www.g1ogy.com/qqv-0640.html
-===== Hacklab ARC =====
+Better photographs of the inside are here: https://pa0fri.home.xs4all.nl/Lineairs/EDL144/EDL144%202m%20amplifier.htm
-  * Call MM0RHL.
+He (Colin's Dad) would have used it with an Icom IC-211E radio which (from memory) had a 10w output - I think the amplifier produced maybe around 100w or so, but this is from old memory so take with a pinch of salt.
-===== Weekly Net =====
+I suspect it could be modified to work on HF - e.g. http://www.zl1bjq.co.nz/qqe06p2.html or http://www.vk3nx.com/files/50MHzAmp.pdf
-Chris will throw out a call Weds evenings at 7PM UTC(TAI), so keep an ear out.
+It probably hasn’t been powered up since 1981 or so - so no idea what condition it might be in - but it might be interesting for radio folks (assuming there’s a large enough dummy load!). Alternatively, if it’s not suitable for hacklab and anybody wants it please feel free to take it, or add it to the ‘dispose’ list.
-===== "Radio Night" =====
+But - high voltage, high power valve stuff = dangerous so be qualified.
-| Date | Theme | Comments |
+Regards,
-|12/02|HF|40m dipole tested with great success and some DX was worked.|
-|26/02|ARDF|A fox was built and successfully tested using a Baofeng UV-B5 > Nagoya SP45, Arduino|
-|12/03|2m Yagi Build|Built some excellent tape measure yagis based on the plans [[http://open-circuit.co.uk/wp/wb-yagi/|here]]|
-|26/03|Cable Tracing|Identified the conduit for running cables ground-to-roof|
-===== Mini Maker Faire =====
+Colin
-It may be too soon for this year but a full license holder could apply for a special event callsign and we could show the station to the public or use it for talk in (providing directions and help to those visiting). Setting up an ardf challenge within Summerhall on very low power would also be interesting.
+"This linear amplifier for 144MHz employs a rugged push-pull tetrode operating in AB2 for the linear amplification of transmitters in the 10-20 watt range. A single stage dual gate mos-fet pre-amplifier is also fitted to enhance the performance on receive. This has variable gain, which is accomplished by varying the potential on gate 2. This produces a gain of approximately 20db in the  maximum gain setting. Under strong adjacent channel signal conditions it may be necessary to reduce the gain to prevent cross-modulation effects in the associated receiver. R.F. input and Antenna connectors are the familiar S0-239 and are mounted on the rear panel and clearly marked. Also mounted on the rear panel are the bias control potentiometer and the mains fuse."
-===== Other Projects =====
+==== Antennas ====
+The lab currently has the following antennae (for transmitting):
+  * Off centre v-shape HF Dipole, this is mostly tuned for 40m/20m
+  * V/UHF Double J-Pole
+There are various other antennae on the roof for SDR and ADSB purposes. Details about these can be found on the [[:roof|roof]] page
+===== Other Projects =====
+  * [[https://radio.ehlab.uk/|radio.ehlab.uk]]
   * [[sdr|SDR]]
   * RX/TX iGate - requires NoV - [[http://aprs.fi/info/a/2M0FFY|this is available]] for the time being for anyone who wants to mess about with APRS.
   * WSPR/QRSS?