AmateurRadio.com

The 'Half-Sloper'

My recent 'topband' blog prompted me to think about some of the more interesting 160m contacts that I've made over the years. Although my first contacts were made just after getting my ticket in the early 60's, I really didn't have more than a couple of watts out of my modified Heathkit DX-20 ... coupled to a short 'longwire', each contact from my mid-Vancouver location was more of a miracle than anything else.


When I purchased my first house in the suburbs in '74, I was finally able to put up a real antenna ... a 'half-sloper', fed from the top of my new 48' tower, along with an extensive set of radials running along the perimeters of my yard. I also hung both 80 and 40m half-slopers from the same feedpoint, giving me coverage on all three of the low bands.

Once the Japanese manufacturers started adding 160m coverage to the various lines of transceivers, the band really started to get popular, as up until that time, very few commercial transmitters covered 160m. Most of the E.F. Johnsons, the DX-100, and some of the late Drake radios were doing the heavy-lifting unless one was enterprising enough to homebrew or modify a rig for 160.

I immediately set out to work all 50 states from my suburban location, running a pair of 6146's at around 150 watts input. It took me a few winters to get them all, with Rhode Island being the most difficult, at #50.
My 160m W.A.S. certificate was #264.

Conditions always varied with the solar cycle but a surprising amount of DX was worked at my low power level. A couple of the more memorable contacts from those days were with H44IA in the Solomons and with VK9NS, on Norfolk Island.


H44IA was worked at 0426 local time in February. I recall calling several JA stations that morning with no response (I always found difficulty working JA on 160) and was more than surprised when the H44 came right back to my response to his CQ.


Jim Smith, VK9NS (SK), seemingly spent more time at various exotic locations than at home. Over the years I was able to work him on a number of his Pacific-island expeditions, but it was gratifying to finally catch him from another rare spot ... his home! This contact was in mid-July, right at sunrise.

I've worked a number of island expeditions over the years on topband, but one of the rarest was in the mid-Indian Ocean, FT5ZM, on Amsterdam Island ... also right at sunrise.


Another 'closer' island has always been a bit rare on 160, Guantanamo Bay, Cuba ... worked in mid- February, just after midnight.


In all of my years in the suburbs, I was never able to hear Europe on topband. It seemed that the noise-curtain surrounding my reasonably quiet location was still just too high for such 'over the pole' west coast treats. It wasn't until I moved to Mayne Island, off the SW coast of B.C., and re-installed my half-sloper, that the Europeans finally began to fill my log. Some nights, during solar-low years, the Europeans were workable before sunset ... on other nights, there were no signals other than Europeans, filling the band from 1800-1830, at times making the topband sound like 20m CW ... definitely not like the city.

4Z1UF was worked in February, just after 8PM local time while R1FJT in Franz Josef Land was worked right at sunset in late October.



Africa is always tough on the low bands but the solar-low years of Cycle 23 brought some amazingly good conditions to the west coast. The two new ones, below, were both worked in November of '08 at around 10PM local time, right at sunrise in Africa.



Learning the quirks of topband propagation is still an ongoing project but over the years, 160m has been my favorite wintertime hangout. With T2GC on Tuvalu Island, worked last week, my present 160m DXCC total stands at 156 worked and 155 confirmed.

If you're looking for something different, some new fun... a bit of an operating challenge ... I know you'll find it on topband!

With all commentary periods for the FCC's 'Notice of Proposed Rulemaking' (Docket 15-99) now closed, it appears that one of the last comments to be filed may contain the most powerful arguments in favor of swift implementation.

In its extremely detailed 42-paged submission, the ARRL states, in no uncertain terms, the reasons why access to both the 2200m LF band and the 630m MF band should not be held back and that service rules should be 'finalized'. Indeed the powerful arguments stated in favor of implementation should go a long way in making this happen sooner rather than later.

The FCC's position is that there is little to no evidence to indicate that amateur radio operation on either band would be incompatible with power company PLC systems, going as far as stating that at distances of 1km or more from PLC lines, "there is no chance of interference". Further supporting their claim, the thousands of hours of experimental operation were offered as powerful proof and that the ARRL was “unaware of any reports of interference to PLC systems arising from that operation conducted pursuant to numerous Part 5 experimental licenses…in the large band utilized by PLCs.”

In addition, the ARRL had harsh words regarding the FCC's attempt to legitimize the growing number of fish-net beacons in the 160m band, and pulled no punches regarding their position in this matter.

"There is no indication that these buoys are compatible with other uses in the band, no track record of interference avoidance or resolution, and certainly no indication that the current operators can be relied on for compliance with the Commission’s rules."

"The Commission is urged to avoid enacting rules that it has no effective ability or intention to enforce. That fishing vessels have, with impunity, illegally deployed radio buoys in this band on a widespread basis (whether or not due to misrepresentations of the importers and retailers of these devices or due to a disregard of the Commission’s rules generally) without even nominal enforcement actions by the Commission, provides no basis for assuming that there will be compliance with any deployment limitations (including geographic deployment restrictions) on these buoys going forward. Nor is there any basis for the assumption that there will be any enforcement action taken with respect to continued illegal operation of the buoys if and when interference is caused. Spectrum planning by the Commission in this context has to be based on ex ante determinations of compatibility rather than mere assumptions, especially where the record indicates such a low level of historical compliance."

A summary of the comments can be read here in the ARRL News while all comments filed for the NPRM be found here temporarily, while the FCC site is down for maintenance.