630 Meter Test

[James Hadlock]

630 Meter Activity Event

 

An announcement on the Pacific Northwest VHF Society reflector of the February 4th 2nd Midwinter 630 Meter Activity Event from Steve, VE7SL, caught my attention last week.  I've never heard signals below the AM Broadcast Band and thought it would be interesting to see if I could hear the VE7 stations scheduled to be active. 

 

The first project was an antenna.  I remembered from my pre-Novice pre-SWL days when I was a Broadcast Band DXer with my AM Clock Radio (best DX was Wolfman Jack on XERB) that the more wire the better.  The longest piece of wire I have is an 80 meter radial (66 ft) from my 5BTV vertical, so I strung it up as a sort of inverted L up about 25 ft.  I figured I'd need an antenna tuner to peak it up so I got out my MFJ Tuner and a ferrite choke for the coax between the tuner and radio.  My K3 goes down that low, so I gave it a try.  Not having the general coverage band-pass filter option, I think I was working through the 160 meter filter in the K3 - whatever, I was not able to hear KOMO on 1000 kHz or KVI on 570 kHz - not good.  So I switched over to my trusty IC-706MkIIG which has been my go-to portable rig for the past 10 years.  I was able to hear the AM Broadcast stations now but not as loud as I expected, and the antenna tuner didn't have much effect.  Next I changed tuners - I have a homebrew tuner I've used on 160 meters in the past and that replaced the MFJ.  I could still hear the AM Broadcast stations, but tuning didn't make much difference.  Using the Pre-Amp in the radio introduced a lot of noise and birdies so that was out, and I never knew if I was hearing real noise and signals or birdies.  So I put a wire jumper straight from the input connector to the output terminal of the tuner - and things got better.  The AM Broadcast stations were S9+ and I was able to hear the WSDOT Traffic and Parking transmission from SeaTac airport on 530 kHz AM.  So that was the setup I went with for the Saturday night test.

 

VE7SL was scheduled to start on 473.0 kHz at 0200Z (Feb 5th UTC) and I heard him come on and start CQing at 0152Z.  He made several calls announcing his QSX frequencies (3526 and 7115), and began working stations.  Paul, K7CW, was his third QSO at 0218Z.  At that point I had a thought - I'm hooked up to a quarter-wavelength wire on 80 meters, why not try using it for a transmit antenna and see if he can hear me?  So I got out a key, and tried the IC-706 into the wire on 80 meter CW - SWR was below 2:1, good enough!  At 0237Z I worked VE7SL - he gave me a 599 and I gave him a 579, pretty cool!  I listened around the other announced frequencies and at 0258Z heard VE7BDQ start CQing on 474.0 kHz.  Paul, K7CW, worked him at 0307Z and I worked him at 0315Z - his QSX frequency was 3533 and the CW Sprint was on the band, lots of QRM on 80!  Listening off and on through the evening the signals from VE7SL and VE7BDQ remained audible, but went down as it got later.  At 0500Z I heard a beacon from "WD2XSH/20 LOCATED NEAR BEND OREGON CN83" on 471.0 kHz about 569.

 

The results exceeded my expectations!  I had hoped to be able to hear the VE7 stations.  VE7SL has a website and blog describing his activities, turns out he has worked ZF1 on 630 meter JT9!  So Seattle isn't DX for him, HI!  But BC was DX for me.  Perhaps we'll get a allocation for a 630 Meter Band one of these days - who will be the first to get DXCC 630 Meters?

[Edward R Cole]

James,

Enjoyed your blog on trying 630m reception.

I did not get repairs done before winter snows so my 43x122 foot inverted-L is stored in my shed until spring.  I have heard Rudy- WD2XSH/20 a couple times and my CW beacon heard as far as Buffalo, NY (about 4,000 miles).  Winter is the best time for long distance work on this band as summer brings much lightening static on the band in the lower-48 (summer is actually quiet in the southcentral coastal area of AK).

I run 100w CW or digital using a modified surplus NDB (non-directional beacon) transmitter that I picked up for $40.  It has its own 55vdc PS and completely transistor.  I have used my SDR-IQ or the K3 previously down to 495 KHz near my allocated  frequency for WD2XSH/45.  I have yet to install the new synth boards and modify the gen purpose band filter for use below 500-KHz.  The original filters in the K3 reject signals below 1.8 MHz in order to enhance use on 160m.

I have a KX3 which hears quite well on 630m (472-510 KHz), but it not set up for running mw power drive like the K3 transverter interface is.  The NDB takes 0.1mw for full output as I drive where the original xtal LO was installed.  That is filtered and boosted by a 2N2222 to drive the predriver and final stages of the NDB.  That is run on RG-213 to the bottom of the antenna base coil (turn 2) for matching 50-ohms.  Efficiency of the inv-L is less than 1% so most of the transmit power warms the ground instead of radiating (est ERP is 4.3w).

Ground wave on 630m is extremely reliable out to 150 mi up to 300mi.  I ran a series of tests one summer at noon on Saturdays with a ham north of me 70 miles and he copied my beacon SNR= +30 to 35 dB,  consistently. He has his own experimental license: WE2XPQ.  One can tune for a few existing NDB beacons between 250-KHz and 514- KHz.  I have heard them regularly out to 1000-mi in AK.

I encourage you to ether get the modification kit or a modified gen purpose filter for your K3.  When ham radio is authorized the K3 is then ready for use (you will need an amp from 1mw to at least 5w and suggest 25w would be better.  Expectations are that output will be restricted to either 1w or 5w ERP (25w will run about ERP=1w).

Flag or pendant antennas work well for receiving in the 630m band (loops are quieter than random wire).  Small magnetic loops of 4-foot are useful for Rx-only.  They need a good preamp designed for 500-KHz (J-310 transistor is good).

I may try listening with my 80m invert-V with coax shield shorted to center connector make antenna a top loaded T antenna.  But too busy at present to do anything on 630m.

73, Ed - KL7uW, WD2XSH/45

--
~The Voice of the Pacific NorthWest VHF Society~
You are subscribed to the Google Groups "PNWVHFS" group.
To post to this group, send email to PNW...@googlegroups.com
To read message history, visit http://groups.google.com/group/PNWVHFS
---
You received this message because you are subscribed to the Google Groups "PNWVHFS" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pnwvhfs+u...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

73, Ed - KL7UW
  http://www.kl7uw.com
Dubus-NA Business mail:
  dubu...@gmail.com