President Madison
The Bentley of ancient CB radio.
I bought this rig via a local auction website. It is fully functional and has the following specs:
- 120channels, 40 low, normal, 40 high
- AM/FM/LSB/USB
- +10KHz switch for the so called Alpha Channels
- Upgraded power supply
All is due to modifications done, as the unit originally only has 40ch and AM/SSB.
The mic is neccessary for operation of the speaker. Need to get that fixed sometime, cause I do not use this rig for TX.
The sound is lush and shows good selectivity. On opening the hood I found a real SSB IF filter having 6 crystals. Now that's truely amazing !
Now take a look at those large meters, they are dying for or what?
Es?
Ah yes, I'm drifting off again. Sorry about that.
The Madison is for 3 days in use now and usually parked on 27.555 (triple-five). Its sensitive receiver shows Es openings already from 09:00 (local) onwards from Italy (what else is new) and later Spain. At 10:30 the band is filled with many loud signals from all southern Europe.
And 6m, which was quiet for two days in a row, is starting too. I'm hearing Italy, Greece and some Ukrain stations.
The Es openings on 27MHz come in waves too, just like 50MHz. However, there's always life on CB, whereas 6 usually stays total quiet in between.
I need to start becoming active on 28MHz again.
Seasonal holidays on Thursday and Friday.
Two days free from office stress.
Dry sunny weather.
Fresh Diemme coffee beans, grinder and Gaggia Espresso machine.
YL on a 5-day trip.
These are the perfect conditions for a few days out in the wild. Errr... the antenna backyard that is.
Step 1: collect aluminium
Collected all aluminum of the 7el 50Mhz long yagi which we succesfully used in HB0_2008. Taped it to my bicycle and of I go. What a nice way to start the day :-)
However, it turned out I missed the long middle boom-section. So after a nice espresso & cappuccino we collected the other antenna parts, including another 5el version, also home made. Us have plenty of (home made) antennas by now. It has paid off well. Both in the fun of building them, as well as using them.
My hybrid sports-bicycle has a pretty short wheelbase. And that is VERY scary with this pile of alu tied to it. As soon as you make a turn the alu is trying to keep going straight ahead and starts shaking its head and tail. The whole bike starts oscillating and that makes each road turn a struggle.
The second standard dutch city-bicycle (ages old model) did not suffer from this effect.
Step 2: build antenna
Empty transport boxes from last summers HB0 dx-pedition. Find baseplate, connection box, coax transformer and several brackets. Locate that carton of very special screws. Drink some more espresso & cappuccino.
Start building the element brackets again.
TiP: through the process we learn that it (would have been) is very important to proper indicate all parts involved, for future reference (yes, please?).
That ends day one. Time for some espresso & cappuccino.
Step 3: mount mast construction
Local rules and neighbourhood control prevent us from building a giant mast. But an antenna is an antenna and certainly beats no antenna. Next, Rens' garden has an almost free view to the west with very low noise. Opposite to my home situation, which makes this a valid remote rx site. Now let's start with some fresh espresso & cappuccino.
Stones are 10cm thick. A special mounting screw for professional use in machinery is being used.
Top bearing and G-1000 Yaesu rotor are added. Time for some lunch and more espresso & cappuccino. Not that you think we started already at "ooh-eight-hundrud". No way, it's holiday time ;)
Step 4: hoist up the antenna
At this relatively low height the antenna is easy hoisted up and mounted to the mast.
Both seriously sweating here under the direct sunlight. Now the 20m Ecoflex-15 (15mm dia) coaxial cable is attached and connected to an Elecraft K3 +pre-amp.
Let's catch some multi-hop-Es dx.
Fire up all equipment...... and .....
Band closed.
Time for some more espresso & cappuccino.
The 50MHz 7element, PA3FGA design @10mtr AGL, QTF caribic.
Step 5: fresh pork
Earlier this day we visited an 'old fashioned' butcher. One which cuts the meat in their back shop. Not any vague import meat from far-far away. No supermarket pre-sugared-thin-slices-crap.
Make fire.
Start with some lovely marinated spare ribs.
Next the real stuff.
Only meat today.
Certainly NO vegetables or salad-trash to upset your stomach.
Now, there's always room for a finishing espresso & cappuccino.
Ok, what's wrong in this picture?
Issue #1
N-socket nicked, coming loose from its mounting plate.
Also some nickel plating chipped off on the right.
Result from rough handling? Wrong tools / overtightening the applied N-connector?
None of this all.
Its the Heavy Duty N-connector and Ecoflex-15 (15mm coax) which did this in just 2.5 weeks during our last fieldday setup in HB0 at 2020mtrs ASL. Despite the coax being taped to the boom, it put too much stress on the socket while being turned. Needs better fixation against self rotating,more slack around the rotating mast etc... next time.
However....
Looking at this type of socket we need to invest in better quality stuff whenever it matters (doesn't that always?).
It became a habit of locating a good deal (read cheap) of connectors & sockets at every hamfest we visited. Nowadays we are more serious on buying large qty's of the good stuff together with other hams from:
www.RFParts.com
UKW Berichte
Kabel-Kusch
So the nickel-crimped version is exchanged for a machined silver teflon version.
Issue #2
Spotted the rust color on the top edge of the socket on the 1st picture?
That's not from the socket, since these are made from chrome plated brass. It's the 4 mounting screws.
From the local DIY store, type galvanized. Equivalent to: lasts one weekend.
Now you might think "buying Stainless Steel ends this, right?".
Not really.
There are plenty of "SS" versions around and the ones with real durability are difficult to find. Your DIY store probabely only has the (again) cheap version available.....
So..?
I know; not every single screw needs to be 100 micron goldplated, navy-proof and such.
But think again when you come across the next auction of cheap stuff.
Trick 1a: monitor Es propagation on 27Mhz SSB
For 2009 I promised myself to pull some extra rabbits out of the hat.
Remember the old CB SSB contacts during the evenings in the 80's? We thought that making contact with South-France, Spain, Italy etc.. was the ultimate dx. What did we know about Es propagation back then when I was only 16? With 12W in SSB, 120 channels etc. (non-legal) and a simple half wave vertical on the roof, next to girls&cars life was exciting to the max!
So why not monitor some CB SSB frequencies to detect Es openings?
A quick jump in a pile of old gear and I dig out both a legal CB rig (22 channels, 0.5W and FM only) and a typical flea-market-worn-out-120channels SSB true DX-rig.
Within milliseconds after switching it on I receive colourful memories from the past; it's that analogue S-meter. This type S-meter was used in most CB rigs in those days and although it looks miserable small, it resembles my youth. I have stared for zillion hours at that tiny needle. Those were the happy days. Yes sure they are.
La Lafayette seems way off frequency, the SSB section is horribly mis-aligned, no TX, but who cares?
Ok, now where do we connect it to?
Trick 1b: a quick home made vertical for 27Mhz
That shouldn't be too difficult. Grab a short fishing rod and cut some wire.
The quarter wave vertical, using 1 radial, is quickly mounted to the side of the chapel roof. Some fiddling with the antenna analyser and we're done, right?
At first I get a resonance at 25.2MHz and it seems parked there, no matter what lengths I cut. It turns out to be the the aluminium strip at the roof front edge, which is very nearby and exactly in resonance at...... Anyway, moving the radial just 1m away from it and the resonance goes up more than 3 MHz. Now both lengths are too short! I feel like an idiot.
Anyway, half an hour later we have CB antenna capability in the building.
The Lafayette offers muffled LSB signals from Mediterranean countries, thus proving there is Es going on.
Can you remember the 'old calling frequencies'?
26.620 South Africa
27.450 France
27.555 General calling freq. but mainly Italy
27.765 Germany, Austria, Switzerland
27.805 Holland + Surinam
I think I better keep it parked at 'triple five'.
Let's see what this trick will offer me, besides some nostalgic feelings :)
Worked some more countries on 6m during Es: 9H1 and an IT9.
2009 Sporadic-E Season on 6m has started !
I witnessed some minor Es openings on two evenings in a row, but that was between Spain, Italy and SV.
Never expected it would happen up here in Holland that soon.
However, this afternoon we enjoyed a short but strong opening direction South Spain, Marocco and the Canary Islands.
I managed to work EA9IB. That is country #4 this year.
See ON4KST screenshot below with lots of humor in the text.
Another measurement?
I like spending my hobby time spinning that VFO, searching for that new signal, working a new country, give away points in a contest etc.. I'm not the type who sits hours at his workbench doing some serious measurement, endless building/soldering etc..... unless, it can bring me new qso's.
Nothing beats being able to hear more, unleash another layer of signals from the mud. For that reason I like trying new hardware; other antennas, other RF equipment.Being able to make that extra QSO yes/no. That is my most important criteria when doing experiments.
While there is plenty of well documented information on the web, every now and then you really do need to verify matters before making a decision on what step to take next.
The Perseus as a measurement tool
I have shown earlier that the new Perseus SDR receiver has some pretty good options in its receiver user interface. I did some quick 6m band frequency sweeps in 3 major directions, see my previous blog. Having the Perseus on loan for some more time, the next logical step would be to do noise mapping at my current home for 50 and 144Mhz.
Current antennas for 2m: 17el and for 6m: 5elWhat exactly is being measured?
A band segment of 6.3Khz is carefully monitored for its band noise level. I have chosen 144.461 as the centre. This is right in a clear spot of the beacon section. The found level of background noise is noted and put in a table.
This is time consuming since you need the level to settle in on the averaging and you want to monitor the band behavior for some 20 seconds at least. After some practising for a day or two, I was able to make reliable measurements within 0.5 dB.
The antenna is turned in steps of 10 degrees. In total 38 directions are monitored; the two steps overlap are for verifying earlier found values.
IMPORTANT: the diagrams show the difference from the quietest measurement. It does NOT show absolute noise levels, only the delta.
144Mhz noise mapping at my QTH
The receiver set-up consists of the following:
17el Tonna yagi @13mtr AGL, aperture angle@-3dB:33 degrees
25mtr Ecoflex-15
Elecraft XV144 transverter, including the crystal oven option
Perseus SDR receiver
Settings: span 6.3Khz centered at 144.461MHz, averaging at 80%
Time slots: 00:30 UTC, 07:00 UTC, 11:00 UTC, 18:30 UTC
Comments on the 144MHz radar view at PA5MW:
The worst directions offer between 6.5 and 9.5 dB more noise disturbances. Go figure! Even in the middle of the night(00:30 is at 02:30 local) there is a horrible RF noise from 3 major directions.
My house is at the east border of the town. I'm lucky that my QTH is at a slightly higher level(+2-3mtrs); at the highest spot in town. I recognize the quiet area from 30 -160 degrees. QTF 290 is pointing at 6 apartment buildings, 10 storeys high, which are at a distance of about 1100mtr. QTF 190 I cannot really explain yet.
In order to verify the whole testing procedure, I did a similar quick test at the QTH of PA3FGA. Rens lives in a much smaller town(2240 inhabitants, compared to the 30000 in my town). His set-up has the exact same 17el Tonna yagi antenna and the same Elecraft transverter. He is able to extend his tower to a max height of 24mtrs. Because of wind and time restrictions we decided to do two measurements; one with the antenna at 12mtrs AGL and one at 16mtrs.
Comments on the 144MHz radar view at PA3FGA:
Although Rens is suffering from much less band noise, he is plagued by disturbances from my city in the direction of 160 degrees. Which is actually the exact QTF for his favourite 2m beacon, HB9HB from Switzerland. The other two lobes point at two other towns. Lowering the antenna involves less band noise, but also less tropo signal from the dx beacon in HB9. We spent another evening finding the optimal height for maxiumum signal/noise level. However, the constant QSB spoiled any possible measurement. From experience we know that 18mtrs is the optimum height for best s/n on tropo signals at his QTH. Due to the wind we were not able to confirm this using the Perseus setup at this point.
50MHz noise mapping at my QTH
The receiver setup consists of the following:
5el M2 yagi @11mtr AGL, aperture angle@-3dB:42 degrees
20mtr Ecoflex-10
Elecraft XV50 transverter, including the crystal oven option
Perseus SDR receiver
Settings: span 6.3Khz centered at 50.087MHz, averaging at 80%Time slots: 01:00 UTC, 06:30 UTC, 12:00 UTC, 18:30 UTC
Comments on the 50MHz radar view at PA5MW:
The giant noise lobe which peaks between +8 and +10dB from QTF 280 to 360 is an eye-opener for me. I have spent too much time on worrying about my less than average ability to hear the USA on 6m. I can work them usually easy at first or second call. No wonder! I simply have 'bad ears' towards that direction because the band noise level is much higher than other directions.
The other big lobe, which is evident on the 144Mhz view, also exists here.
During the night all is relatively more 'quiet' than on 2m.
One can also pick the wrong time slot; I started measuring at 17:45 UTC when just before 18UTC the noise suddenly became outrageously high. What had just happened? Well, since the start of television people turn on their TV's for the 8 o'clock news. During the first minutes a tv produces its peak of EMC noise. I waited some 30 minutes and did the measurement again. The evening disturbance sure is a bummer on 6m.
Conclusions:
- Noise levels at my QTH from various directions differ MUCH more than expected; up to 10 dB on both 144 and 50MHz.
- My direction for dx would be roughly east between QTF 30-160
- I cannot concur that with pre-amps, better rig or just another antenna
- Going extremely high and using a stack with a low noise temperature is not feasible for me
- Live with it and change operational tactics to make the best out of it
Does this mean I cannot work dx, not have any fun anymore? No, of course not. First of all, my current QTH is a lot better than my previous location. That was in the middle of a large city, and although my antennas were at 19mtrs AGL(6m higher than currently) I suffered from even more noise in every direction.
One very important matter: no hardware is going to solve that wall of 10dB noise.
Next question is: what is the relevance of those found minimum levels? When is your QTH a quiet loation?
In order to do a comparison test we need to design a portable setup and do several measurements at many different locations, both urban and very remote.
For now I need to accept the situation and make the best from it.
It is what it is.
New goals for 2009 6m season
The 6m season will start in a few weeks. There are a few enhancements on my wish list.
One of them is to link my Elecraft K2+XV50 transverter to the Kenwood TS570SG.
Why would I want that?
Make use of the best ergonomics
On 6m it is usually a matter of seconds to find the dx and make the contact. Better rig ergonomics do help a lot. The Elecraft K2 has a great analogue receiver but ergonomically for me it is very annoying. The TS570SG has superb ergonomics, and a quick& friendly user interface.
Better TX signal from the TS570SG
It has a much better mic compressor, high-boost equalizer and 100W output on 6m.
The K2 +XV50 has none of that.
Make use of a second RX
- For monitoring a different frequency.
- Because I want to try some semi-diversity (pseudo-stereo) in the audio chain. That requires some more work; like a second switch able antenna and switch able audio routing.
-
Finally because the RX quality of the K2+XV50 transverter might offer better performance. Well this one has to be proven yet, since I have already modified the TS570SG again to make it a dedicated 6m rig only.
Remote operating
It will serve any remote operating experiments too.
Conclusion
I want to operate the TS570SG, but be able to co-use the K2 on the fly.
A programm to master-slave the K2 to the TS570SG
Since the K2 uses the Kenwood protocol, it is possible to create a program which enables to make the K2 follow the TS570. I'm fortunate that Arnold wrote a small program which just does that. It reads the current VFO-A frequency and writes this to the K2's VFO.
After just two evening sessions we have a raw but working program. I can now turn the Kenwood's VFO and the K2 follows quick enough to avoid any latency and such. We still need to work out some minor bugs and make it more operator friendly, but for now it already does what I wanted. Great job done Arnold !
There a some minor frequency difference on the readouts of both rigs, but that is due to the offset of the K2's 6m transverter. It is key to zero-beat both receivers. I have to do a lot of testing to see if both behave well and do not suffer too much from thermal drift and such. A quick user offset setting will probabely be the next added option in the software program.
Buy another rig?
Now you might ask why don't I buy a new, better rig with dual receivers (or dual watch) and everything else I need? Well there's the financial aspect, and more important, I'm not ready to give up on the 570 yet :)
PERSEUS
I'm lucky to try out the new PERSEUS SDR receiver from Microtelecom.
I have seen it in action at Rens, PA3FGA for several weeks now. It IS a great device.
What I like most of it:
- It does have a great receiver
- Very informative GUI, much better than any SDR competition
- Can show both waterfall bandsweep and separate FFT spectrum on the received passband
- Can record 800KHz band segments at a time (record the 48hrs contest)
- Has reasonable measurement capabilities for frequency analysis
The waterfall view together with a small bandsweep and proper averaging settings is the way to find weak ones. I have seen proof on very weak beacons on 144MHz (from my Elecraft XV144 transverter output). I have also watched a recorded night of ARRL-DX-CW contest on 160m. You can spot the weak ones next to the big pistols. Yeah key-clicks are now visual too on some of you :)
Measuring device?
This is a consumer device, but with valuable user settings and good specifications.
As such, it can be a reasonable measurement device with which you can do some rudiment frequency analysis. It is capable of showing clear raw data you can trust.
Now what has it shown me so far?
My current location at the east outer border of a small town has shown me already that I suffer from noise and in band disturbances on both 50 and 144 MHz. When turning the antenna, both the ground noise level rises and several in-band local disturbances turn up.
For 50MHz this is very obvious when turning the antenna to the N-W direction (my town).
Time to do some of that frequency analysis.
I did a bandsweep from 50.000 - 50.200 MHz using the following setup:
5el M2 yagi @12mtr AGL
Elecraft XV50; 50Mhz to 28MHz transverter
Perseus SDR receiver set at 200KHz span and averaging set to 80%
6m band direction N-E (QTF 60deg)
The window is centred on 28.100, which effectively is 50.100 MHz. The transverter is aligned and has the crystal oven build in. Do not look at shown levels and such as this depends on many factors.The disturbances on 060, 090, 120 and 150 are local man made QRM.
6m band direction South (QTF 180 deg)
See the effect of local noise? The band noise level has already gone up by 5 dB and new other disturbances turn up.
6m band direction N-W (QTF 290 deg)
Even more noise and stronger disturbances.
The measurements where made at 03:00 in the middle of the night (01:00 UTC), when all is quiet. Right?
Think for a minute what it might look like during daytime, or even worse, during evenings?????
Preliminary conclusions:
This is a quick&dirty band scope view only. It only shows the 'Big Picture'.
It might explain, to some extent, why making contact to the USA on 6m is so hard from my current location. However, there is much more measuring to do before jumping to conclusions.
Next?
Perform extensive testing in more directions, at different times during the day.
Repeat the measurements to average out any large variations.
Another one?
Yes; in my previous blog of January I mentioned needing another splitter.
It would need a better spec at 28Mhz. The IF output frequency of my 144Mhz & 50Mhz transverters.
I have plans for:
- analysing signals during reception
- comparing different IF rigs at readability
- combining different IF rigs to create sort-of-diversity reception
And not for?
This blog is not for writing a paper on already existing applications, home built equipment and such. There are lots of other, better web resources for that, like: W8JI, VK1OD, hard-core-dx to name a few.
I just want to record my findings and describe the equipment used while in the process. It will serve me when picking up a project again in the future.
What do we have so far?
A quick & dirty W8JI style Magic-T combiner, using #73 ferrite binocular.
The frequency sweep shows the port to port isolation from 1 to 30Mhz.
W8JI version Magic-T splitter_MKII
A more serious attempt this time, using:
- alum die cast box
- #43 ferrite binoculars
- 24 AWG red enamelled wire
- BNC chassis parts, pop riveted to the box
- 1W 100 Ohm metal film resistor
I have ordered carbon composite resistors. If that offers a significant better specification at 28MHz I will do some more testing and create additional versions of the splitter. When time allows.
How do they compare?
attenuation port to port isolation
1.8Mhz 28Mhz 1.8Mhz 28Mhz
MKI -3.52 -4.33 28.0 15.5
MKII -3.05 -3.30 38.0 19.2
Remarkable that using #43 ferrite brings better specs at 1.8Mhz, right?
There sure are other possible reasons for that: using a shielded box and different wire.
Other remarks:
Port 1 to Port 2 isolation and vice versa differ 1 to 1.5 dB.
The measuring coax cables have been calibrated in the test set-up by the HP network analyser.
The cables (RG58) might have a small negative influence on the isolation measurements due to the limitation of their shielding.
Satisfied?
Yes; it has low attenuation, sufficient port-to-port isolation and it is easy to reproduce.
Let's get using it and do some of the tests I've on my mind.
I'll be back.....
For the sake of making contacts on the 'upper' Low Band I decided to do a quick & dirty GP set-up for 7Mhz.
The current 'Simple HF Multi band Vertical'(see previous blogs) had to go. There's no sunspots to expect in the next coming months, so no interest in the NCDXF beacon monitoring station currently. Even more because I have Hi-jacked the TRX (TS570SG) for the coming 6m season.
How to create a simple backyard GP
1. Make a full size radiator
Take a typical fibre glass fishing rod and any kind of conductive wire. Note: insulated wire intruduces a velocity factor of about 0.92 - 0.97, depending on the insulation type and thickness. Now start calculating the 0.25 wavelength, using the lowest frequency you want to be able to use; add another 5 % for adjustment.
Slightly spiral wind the wire around the rod and use electrical vinyl tape to fix it.
2. Install a ground rod
Just hammer(-drill) down any kind of 1-3m length copper pipe. It serves as a lightning rod and makes a good bonding point for the radials. Note:it is does not protect against a direct hit. When zapped by lightning it might avoid that all your shack-gear is toasted. There's lots of good websites on that subject so take proper care and be responsible.
3. Lay out some radials
Again; use whatever conducting wire you have available.
My backyard is 7 x 8 mtrs and the GP is mounted right at the corner. So no space available for 120 even spaced 'full size' (what is that crap?) radials. Just lay down whatever you can manage. I have 9 lengths between 4 and 8mtrs spread around the backyard. It covers 110 degrees around the GP. Why not 360 degrees? Simply because there is no space available.
4. Add a current balun.
Take a proper piece of ferrite (FT150A-K), put 8 windings no 16 AWG Thermaleze wire on it. Some 10-12 windings of thin teflon coax on a proper ferrite will be a good alternative too.
Use proper protection against moist.
4. Adjustment
Do the adjustment after you have layed out all radials. Adding more radials can alter the radiation resistance and shift the resonance frequency, certainly when you have only a few lying around like in my example. But my point was not to create a High-End antenna (what is that?), only to start being able to make contacts on another band.
How does it perform?
We have a full size vertical (3 out of 3 points), a ground rod + 9 short radials, covering only 110 degrees between north and south-west(1 out of 3 points) and a tiny backyard in a small village (2 out of 4 points). That makes 6 out of 10 points on the 5MW scale.
Within 24 hours I make numerous contacts to the USA and several to Asia. There are no radials in the direction of Asia, but I get through the pileups of BY and BV without severe drama involved. My operation is CW (only) and at a max. of 50W
Let's face it; ANY kind of antenna will allow you to make contacts. And depending how many effort you put into the process, you can master fine dx contacts at will.
Am I happy?
The antenna is up since February 6th and does perform as one might expect.
However, I kind to start disliking the band. Or today's hamradio operators behaviour to be more exact.
The art of rudeness and jamming from so many, makes me shutting of my TRX to often. If I would be able to put more effort into a directive high performing receiving antenna I might avoid them a bit. I also wish the dx-clusters would cease to exist. Tomorrow please..... ??
Anyway, time to return to my roots on the Low Bands: 160m !
