How to Operate QRM-free SSTV




The QRM situation in1998 is tougher than ever for SSTV. There are several Hints and Tricks to be able to run QRM free SSTV.

After nearly 30 years in the air as a SSTV operator, I have had the advantage to follow every step in the evolution of the SSTV mode. I am working 2000-2500 SSTV QSOs yearly and am holding the WW DXAA AWARD #1 for SSTV. I have worked more than 130 DXCC countries on SSTV and won WW SSTV contests 15 times. With this background, I feel entitled to give SSTV newcomers and others some hints and tricks on how to operate SSTV. The total QRM ANARCHY that we now unfortunately have on our bands must be avoided. Spread out your SSTV activity on the SSB portion of the band, and operate SSTV as you operate SSB. USE THE MICROPHONE and operate ± 3 kHz from other stations. To understand this we have to go back in history.


History: Few SSTV Operators - No QRM.

Let us look back 30 years and we find that our SSTV segments, 3735 - 7040 - 14230 - 21340 - 28680 (all + - 5 kHz), where QRM free. This was because of few SSTV stations, perhaps 200-300 operators WW. Rumors has it that these segments were taken as SSTV experiment frequencies in the USA, IARU Region 2. These segments became WW SSTV frequencies and adopted by Region 1 and 3. The mistake was that their location was in the middle of the telephony bands. This became a huge WW SSTV problem at the end of the 1980´s. The Fast to Slow Scan and the Slow to Fast Scan B/W digital converters, together with the high resolution digital Color SSTV converters, conquered the SSTV world. Today the SSTV is dominated by PC based systems, which makes for an easy start up and operation. At this time, we have about 2000-3000 SSTV operators WW. The 10 kHz space is narrow and it has now become 10 kHz of continuous QRM.


SSTV Segment Of 10 kHz Is Too Narrow; SM5EEP Reacts As Well As Region 1.

I realized the problem at the end of the 1980´s and asked the Swedish Amateur Radio Society (SSA, Föreningen Sveriges Sändareamatörer) for help in 1990. In 1992 we introduced a bill (C4.15) to the IARU Region 1 asking "How to improve the conditions for HF SSTV?" The Region 1 meeting in 1993 gave us a SSTV working group; whose chairman ZS6BTD received a of input from operators. Most of the input demanded wider segments, move the segments, let us run SSTV on free frequencies within the telephony (SSB) portion of the bands. These points, together with other views, were discussed at the IVCA SSTV forum at the 1994 Hamvention in Dayton USA (see below). There were representatives from all 3 IARU Regions. The summary from Dayton served as the input to Region 1. The Vienna meeting in 1995 gave the following answer (HF/Doc.93/DHB/C4.15):

"It is recommended that the frequencies 3.730; 7.040; 14.230; 21.340 and 28.680 MHz should be as calling frequency for SSTV/FAX operators. After having established contact, the station should move to another free frequency within the telephony portion on the band"

After five years of hard work the SSTVer can finally, and legally, operate outside our regular SSTV segments. I do not know if the above recommendation is known or published in all of Region 1 countries. If it is not, then ask for it. Today in 1998 we are 4000-6000 SSTV operators WW. The recommendation is good news for us, but this also brings problems to our bands in the form of QRM. We have to spread out our activity outside of our regular SSTV segments. We need guidelines and a great deal of cooperation among ourselves on how to operate SSTV smoothly and QRM free.


The Well-Known European QRM.

Today many are calling CQ by video on the same spot (for instance 14230) and at the same time. This is done without saying a word or watching the screen to see or hear if stations are calling back. The continuous calling without voice makes DX stations frustrated. They call this habit "The well known European QRM". SSTV is a complement to SSB and the old basic idea for SSTV is to mix VOICE and VIDEO as stations do in Regions 2 and 3.

While operating CW-SSB or other modes, we do not interfere with other stations as much as with SSTV! The main reason must be that newcomers and others still make sure of the sharp 10 kHz limit of our SSTV segments. Read the Region 1 recommendation again! We can, as I said earlier, fully and legally operate outside our regular segments within the SSB portion of the bands.

Newcomers and others have to understand that on the same spot and at the same time, only one (1) station can call a QRM free CQ. You also have to wait to see if the CQ station gets an answer BY VOICE! If you would like to work the CQ station, give him a call BY VOICE. When the contact is made, both of you must move to a clear spot which is 3 kHz up or down from any other SSTV or SSB station on the telephony (SSB) portion of the band, (leaving the CQ spot, for instance 14.230, free for others CQ),. This is exactly what Region 1 asked us to do.

We have language barriers in Europe, but remember that all of us have the right to call in using our own language or the language we use operating SSB. Operate SSTV as you operate SSB! The language does not cause any problems if we would cooperate and find ways on how to operate smoothly and QRM free SSTV.


SM5EEP: Ways To Operate QRM Free SSTV.


The most QRM producing stations are:


IVCA (International Visual Communications Association).
The IVCA (International Visual Communications Association) was established in 1987. It is a WW informal association for amateur radio enthusiasts who have a high interest in visual communications of all types. KB4YZ, Dave Jones is the President. An annual donation of 10 US dollars gives you the membership. Send your donation to KA4H, Jim Gaither, P.O.Box 140336, Nashville, TN 37214, USA. IVCA mets each year at Dayton Hamvention . The VISION is IVCA newsletter which includes the latest WW news about SSTV, equipments, programs, contests etc. The VISION and other IVCA information find you on homepage


I hope to see all of you on my screen! Keep 3 kHz between stations, use the MICROPHONE and we will ALL HAVE QRM FREE SSTV. By following these instructions, operators WW will again find the European SSTV stations as a worthy of imitation.

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