4X4XM Personal Bio
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Shalom! Doron is my name. Karmiel, Israel, is where I call home. I've always been fascinated by radio. From 1963 to 1992 I was an active amateur radio operator. See my Vintage Rig. After a 28-year break I returned to amateur radio in June 2020. Now I'm looking forward to ragchew with both old and new friends. My present rig is fairly basic. Everything is SDR and QRP in tiny. Due to the recent 25th solar cycle, I've been thinking about how the Sun affects HF radio propagation. Thankfully, advances in Space technology, SDR (Software Designed Radio), as well as the internet As planned, I'm compiling data on HF Propagation Forecasting, doing research, and assessing the findings. This project is frequently updated. See the table of contents. | Topics
* Preface
* Current Rig * Ham Activities * 1965 QSL * Vintage Rig * Education * Professions * Interests * Websites * Networks |
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Preface:
Doron Tal is the name that I use today. Before 1969, my surname was Tirkel. I Started Radio Hamming as a kid in the late 1950's, licensed in 1964 (Novice), and 1965 (General). Due to a busy life, I was forced to be QRT in 1992 and returned back to amateur radio in 2020, this time to forecast propagation of skywaves.
Until recently I was QRV for voice RoIP meetings, Hebrew ragchewing: Due to the security situation in Israel, I am temporarily unavailable at the times specified. QTH History:
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 My First Homemade QSL 1965 |
Until 1965, my entire rig was homebrew. After 1966, I began modifying vintage and surplus equipment.
See the list below for the gear I've preferred over other gadgets I've collected and used over the years.
 In 1966 (age 17) I bought my first commercial receiver, a Hallicrafters SX-110. It was a single conversion (455 kHz IF) general coverage receiver in four bands ranging from 535 to 34000 kHz.
First, I added a Product Detector and improved the Noise Blanker.
Second, I built an external Xtal-controlled front end that converted the higher HF and VHF bands to 3.5, 7, or 10.7 MHz with 50Hz stability and image rejection of more than 75dB. It was considered a remarkable achievement at the time.
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Subsequently I fixed a broken Hallicrafter S-37, 130-210 MHz VHF receiver that I had discovered in a junkyard. This was a true gem that allowed me to search for spurious signals and listen to amateur radio broadcasts, aircraft, ships, and police. In addition, I refurbished and modified the SCR-522 WWII transceiver,
originally covering 100-156 Mhz in 4 preselected channels.  This antenna was constructed from an expanded aluminum mesh in the shape of two isoscale triangles attached to a rectangular wood pyramid.
The transmitter BC625A and receiver BC624A were Xtal controlled.
I added a 10.7 MHz output to the VHF receiver after the conversion stage, which was injected into the SX-110. This configuration enabled easy tuning within the 2 meters amateur band and stable clear reception of CW, and SSB modes. |
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In 1966 the late Erik Friedman MD, 4X4WF (SP5WF), lent me Bandmaster Delux TBS-50D Transmitter (Harvey Radio Laboratories, Brookline, Southbridge, MA, USA) covering 80m through 2m.  I have added a homebrew VFO. |
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16dBi pseudo-Horn Aerial for 2m that was erected in 1966, enabled S9+ QSOs from downtown Haifa, Israel to Larnaca, Cyprus ~270 Km 
This antenna was constructed from an expanded aluminum mesh in the shape of two isoscale triangles attached to a rectangular wood pyramid.
The pyrmid's base and the triangles' sides measure 2450 mm.
The mesh triangles are aligned at a 60-degree angle.
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In 1975 I bought a second-hand Yaesu FT200. It was an SSB/CW transceiver that covered the pre-WARC amateur bands from 80m to 10m and provided up to 180 watts PEP. I added improvements and used it until 1990.
In 1982, I won a raffle for a broken Siemens E311 receiver. I restored it until it operated like new and used it as a high-quality receiver for eight years in my shack, with an accuracy of 100 Hz and stability of 20 Hz over 24 hours.
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While on Sabbatical Leave (1990-1992) in Plainsboro, NJ - the late Sid Gogel, W2FUR (1919-2015) lent me a vintage rig:  This Collins 51S-1 receiver enabled me to listen in New Jersey USA, to the Voice of Israel on HF, and more.
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 Operating this Swan-350 I kept in contact with Israel during that Sabbatical Leave 1990-1992.
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Education: 1977 MSc. Physics (Molecular Physics, Physical Chem., Electro-Optics, Sys Eng.)
Specialties: Scientific R&D, Sys Eng. & Analysis, Management, Planning, Audit, Arbitration, Expert Witness
Professions:
- R&D Physics 1973-1997 (Laser Systems, Combustion, Night Vision, RDF, IDFF, Artificial Soldier)
- System Engineering 1982-1997 (Advanced Physical Systems)
- Project Manager 1987-1990 (Airborne Night Vision)
- Expert Witness 1997-2014 Speed Enforcement by Lidar & RADAR (SHF)
- Control Boards - Volunteer member of Audit Committees (NGOs) from 2006 until today
Interests:
- (since 1960) Radio Ham Activity with a focus on Learning and Experimentation;
I've never been interested in phone contests or awards. - (1964-1975) CW .... .. including contests.
- (1975-1988) Phone Patch - service for hams and family residing overseas.
- (1983-1990) Packet Radio using Commodore 64.
- (since 1988) Increased mortality in amateur radio operators; see also here
- (since 1992) time-out from activity on ham bands because I value my family more
- (since 2004) Public Health, Environmental Protection, EM Radiation Hazards
- RF Radiation and EMF Safety (ARRL since 2010)
- Safety in the Shack (RSGB since 2014)
- Indirect RF Hazards (AF5NP 2018)
- (since 2021) How does Solar Activity affect HF Propagation and Predict HF Propagation
Interests NOT related to Radio Amateur - Married to Ilana since 1974, having four children and seven grandchildren.
- Social Justice, Political Correctness - since 1994, Stop The Abuse of Power
- Genealogy: Searching family roots using the internet since 1997
- Cooperation and Regulation of Israeli Civil NGOs - since 2007
- Israeli Singing Groups - since 2012
Websites:
- What does radiation do to our body? (Hebrew) Google Translate
Websites NOT related to Radio Amateur - The Turkel Tribe website
traces family roots back about 300 years ago.
- My voluntary activity aimed to improve our society; see Doron Tal's Homepage
- Stop The Abuse of Power, since 1994 (an emphasis on אגודת חובבי הרדיו בישראל (Hebrew: Google Translate)
- PEACE & TOLERANCE. since 1997
Public Networks:
- Youtube focuses on Radio Amateurs
- Facebook > login is required to view focus on Radio Amateurs
Last but not least:
The world is changing as the radio amateur spectrum is being sold off to commercial users since few amateurs operate SHF and above.
If you have comments, questions or requests please e-mail me.
73 de Doron