What are the advantages and disadvantages of the end-fed half wave antenna? When the transformer was mounted in its box and the output connected to an antenna connector feedthrough, the observed capacitance increased dramatically to about 6.0 pF. Could it be something to do with the new vertical aerial I had recently installed? Toll Free 800-532-2645 636-532-1523 Fax: 636-532-8259. Krem, rja le, mi a krdse. The original coil is designed for low power portable applications. Radio amateurs using this antenna might remain oblivious to the presence of many active DX traffic originating from the direction of the shadow regions in the nulls. Basu Bhattacharya (VU2NSB). So I built myself an improved replacement matching transformer. Functioning as an, HF Wire Antennas - A Primer When we speak about wire antennas, the first and foremost thought that comes to mind is the 1/2 Dipole antenna. Below is the schematic of the final build. Above, the magenta curve is measurement of a real transformer from 1-11MHz with nominal resistance load and three compensation options: cyan: 0pF, too little compensation; magenta: 80pF, optimal compensation; and. I did struggle with the C in pF calculation..I seem to be getting hung up on the correct decimal placement..for example, for the 40-meter Capacitor requirement, I get .000000000258: C pF = .000001 / [ ( 2 * 3.14 * 7 MHz) ^2 ] * 2 uH Workers' Comp. This could be achieved by increasing the spacing of the windings, hence reducing the interwinding capacitance. 73! Above 7MHz, there is very little temperature dependence at all. No capacitor was installed. No wire counterpoise is used to reproduce the SOTA setup. Let us touch on some necessary theory to begin with. Do your own experiments with your own set up, 2019 - 2022 by Dan Koellen AI6XG. I ran WSPR at 10mW for about 2 hours and got the results below. The 6-turn loading coil lowers the resonant frequency into the CW portion of the 80 meter and higher bands. Frank VK1VK. Proudly created withWix.com. 73 You can achieve this inductance with half a dozen turns of the antenna wire tied in a small coil. However, it has its idiosyncrasies. Even at 15W the voltage at the ends may reach 100-200V. The comparison is done on 4 bands - 10m, 20m, 40, and 80m. The VSWR plots below show results from the same transformer tested on the bench with minimal output capacitance, with a primary compensation capacitor, either 100pF or 27pF included, with the transformer installed in its aluminum box including antenna connector feedthrough, and with the transformer with an 18 clip-lead on the antenna output. Your posting put it all together for meTHANK YOU!!!! The 1:64 transformer is wound on 3 stacked FT240-52 toroids, this provides same. Since the tuners location is best if it is handy for the operator, one end of the end-fed antenna is also close to the operator. . Accordingly, calculate the capacity for the resonance at the highest frequency to be covered with the highest inductivity taken in consideration. Above is a thermograph of the transformer at 20W input at 3.6MHz. This is typically a weak spot. 1. 2 0 obj A/l for the chosen core is 3.5 times that of a FT82-43 yet it is only 1.6 times the mass. The total lenght is about 15mtr only and using 2 coils and a little stub (s) on the 80m coil or/and the 40m coil. Moreover, this antenna produces several inter-lobe nulls creating multiple band dependant shadow regions in its coverage. Evaluating it at a we get: which gives the power dissipation simply in terms of the heat capacity, cooling time constant and the temperature difference from ambient. SWR for 80-10 meter EFHW with no capacitor, SWR for 80-10 meter EFHW with 100 pfd capacitor, The above data from K1RF shows that the SWR for 20 meters (my dark red markings -, I hope to do more experiments with single and multi band EFHW antennas above 20 meters - stay tuned, 40 meter and 20 meter (full wave) SWR with no cap. The technical storage or access that is used exclusively for statistical purposes. Can a diode be used to rectify signals smaller than its threshold voltage? Each geodesic great circle path displayed on the map originates from your location that is derived Read More, The Great Circle Map GCM We present an automatically rendered Great Circle Map GCM based on your location derived from your Internet IP address. All Rights Reserved. The coil uses 26 AWG (27 SWG) enamelled copper wire close wound on a machined plastic former. I think the idea is to begin by tuning 40m operation, adjusting the wire length as needed. The goal of the temperature characterization is to determine how much temperature difference (core to ambient) there will be for a given level of power dissipation. I have an EFHW and the SWR is acceptable on all the bands with the exception of the WARC bands which is to be expected since the harmonic relationship is different. The transformer was attached to the 30 meter EFHW antenna and turns were removed for best match to 50 ohms. Therefore, installation is quite easy, and its tuner circuit is rather simple as well. View the job description, responsibilities and qualifications for this position. inductance as one FT240-43 and is able to withstand 1kW 50/50% duty cycle with help of a cooling fan. I made one quite similar to it but 3T Primary with #16 speaker wire (2 parallel wires) and 15T Secondary close wound just using about one-third of the circumference of the 2 inch toroid. stream It is best to make the impedance matching adjustable, using switched transformation ratio. Don't sweat the digits to the right of the decimal point too much, the SWR readings changed as the feed height and droop of the antenna changed. I am planning to use this latest one at the Field Day next year. Low SSN Why do most Hams find HF Radio so difficult? However, let me write about it from a slightly different perspective that was not very obvious from the articles I read. One end is about 5 meters high on an extended fishing pole. For the transformer, a T130-2 toroid will be sufficient, on which we wind the seconder with multiple taps, as shown in the below table. Very interesting design. The antenna is up. Because of the turns ratio N, the secondary capacitance will appear N2 larger at the primary and will resonate with the primary magnetizing inductance. Although it is simple to build and is a multiband antenna, it has several attributes that . Being end fed, it needs a transformer to transform the higher impedance of the wire to the 50ish ohms the radio is expecting. Two layers of 1mil Kapton tape are placed over the winding. The conjugate impedance matching arrangement of this nature is far from perfect resulting in considerable reactive currents on some of the bands. A krdsem az, hogy a knyv elrhet esetleg pdf-ben is? One possible explanation is that the core losses drop with temperature. As I reexamined my formula, you pointed it out correctly, there is an error in it. The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user. The impedance matching circuit is essentially a simple parallel resonant LC circuit. 100W on a Wire Antenna - Is it good enough for DX? Of course, if both ends are raised higher, it will produce a more efficiently radiating antenna, but the portable and temporary installation is always compromised by conditions given by a location and its restrictions. It is important to consider the voltages on this tank circuit. In the problematic upper bands, the resonant wire significantly improved the in-band SWR compared to the resistively terminate box (purple). Hence, even operating at 1000W on the 160m band, the cores would not saturate with the 5-turn primary. Scaling the small core to higher power levels would mean that the flux level in the ferrite core would increase. There are many resources online that explain the details better than I can, so Id suggest doing your own research if youd like to build one for yourself. Not the ideal antenna, but convenient! Why does antenna radiation occur? My limited experience with these antennas also suggest that one must be cognizant of the RF current pushed onto the feed-line coax. I strung up a nominal 80m half-wave antenna wire into the trees, snaking it through the open screen door to the work bench where I was doing the tests. However, a key restriction is its 25W power rating, due to the small matching transformer. I use shock cord to connect the insulator at the end of the wire to my fence. And of course, a counterpoise with various lengths. Consequently, this is how the capacitance values are determined. A design by VK3JEG is only 66-ft. long, about the size of a 40m dipole. In this case, it looks important. The orientation of these lobes varies with the frequency band of operation thus resulting in directional inconsistencies between bands. I used a section of 40mm external diameter PVC waste pipe and 1mm diameter enameled magnet wire to make the coil. I decided to play with this to see what I could accomplish. I have been using a 40m End-Fed Half Wave (EFHW) antenna very successfully for the last few months and I wanted to extend the design to multi-band whilst avoiding the need to take a . 1) More primary turns and primary inductance improve the transformer efficiency and low end performance. From the condition, it looked like it had been installed outdoors for a few years, so I got it at a good price. The resistance (real) component of the impedance is right where we want it near 50 ohms. = 258 * 10^-12. The finished tran, End Fed Half Wave (EFHW) Antenna Upgrade Part 1 - The Matching Transformer. 100W on a Wire antenna! EFHW Antenna Frequency Compensation Lead 5,144 views Jan 20, 2019 188 Dislike Share Save Steve Ellington 9.92K subscribers 8 inches of wire attached to the antenna post can lower the frequency. I've always had issues with 10m loading up properly so I'll also be adding a compensation coil 78 inches from the feed point on the wire. In this case =1058 seconds, about 18 minutes, is the characteristic thermal equilibration time in still air. I am building an EFHW antenna for my new MTR3b, but do I need to include the capacitor for 20, 30 and 40 meters? Tackling both of these issues at once led to a much smaller, lighter, and less costly transformer with better loss characteristics than previous designs. I first mounted the SO239 connector to the box. VSWR<1.8 over all of HF. Cmzett: Szvetnik Klmn Cmzett: Szvetnik Klmn dvzlm! The maximum B field in the core is proportional to the imposed voltage, as: where A is the cross sectional area of the core, f is the frequency and N is the number of turns. A lot of radio amateurs have made similar antennas to this with larger transformers for higher power handling. The 2 coils are 35uh and 90uh. The procedure was to run for around 30 minutes starting from the box cool at ambient temperature. But Ill find the error of my ways.and there are various on-line calculators to help me ensure I get the decimals and (H, mH, uH, pH, etc.) A Brief Synopsis of the Antenna Features & characteristics, EFHW Antenna Geometry versus Center-Fed Dipole. To compensate for the antenna connector capacitance, the solution might be to add the appropriate inductance on the wire right near the box. The coil is just 12 turns of wire wrapped around a 0.7 inch diameter tube, located about 6 feet past the antenna's feedpoint. I have also had SSB QSOs in Europe, USA and Canada on 20m so havent seen any degradation in performance on that band. The coil uses 26 AWG (27 SWG) enamelled copper wire close wound on a machined plastic former. With very little counterpoise, the antenna is being fed at a high impedance point so a rather large impedance step-up is employed. The bottomline, your putting the relationships of 1) Toroid windings and to measure their inductance together with 2) the required capacitance calculation is exactly what I needed to move forward with my specific design plans. I assume you know the GNARC source for EFHW antennas. At equilibrium, the heat leaving the box due to cooling will exactly equal the heating power input. The 6-turn loading coil lowers the resonant frequency into the CW portion of the 40 meter and higher bands. 5 Band EFHW Antenna 80m-10m | 49:1 End Fed Half Wave Ham Radio DX 27.1K subscribers 19K views 7 months ago #HamRadio #AmateurRadio #EFHW Here are my experiments and modifications with an EFHW. application of Kirchhoff's current Law on a typical EFHW antenna configuration. Looking at several builds and discussions, such as commercial antennas (e.g. The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. On the ends of each winding I slip the end under the last turn and pull tight to lock the winding in place. The tests here were using a dummy load on the transformer, and that did allow confirmation of the design and expected loss at 3.6MHz. The original coil is designed for low power portable applications. A few comments have been made about why the capacitor is needed: 'Improves higher frequency UNUN performance' and 'Compensates for UNUN primary leakage' - K1RF Hi Ajai, Winding the wire manually was a bit tedious but once done I temporarily held the wire with cable ties and checked the inductance. This could be achieved by: Using thicker wire; increasing the diameter/length ratio; using a low loss former. However, I think I made a good choice with a Hammond 1590A diecast aluminum box. Although the original loading coil is very well engineered, I thought I could make a more efficient version given that I did not need to make it 'trail friendly'. Well, in ham radio, everything works. Research salary, company info, career paths, and top skills for Software Engineer - EDI I mounted the transformer on a tree for testing. The in-band SWR improved significantly with this localized inductance to compensate for the boxs capacitance. (LogOut/ It was difficult to work out where it was coming from but I found that it was more noticeable when it was windy outside. The capacitor makes very little difference to the low frequency behavior, but it reduces the input VSWR significantly at the high end. Is it any good? You can find more info here: https://km1ndy.com/diy-491-unun-impedence-transformer-for-end-fed-half-wave-efhw-antenna/. The SWR was measured for each of the three antennas across the CW portion of the bands. We would like to try to fly a kite with a halfway antenna wire and see what miracle we achieve. As it turns out K1RF had similar questions about the capacitor and published data showing that the capacitor does improve SWR performance at frequencies higher than 20 meters. Three EFHW single band antennas were prepared for 20, 30, and 40 meter bands. The coil came out at 89mm in length rather than the theoretical 83mm not surprisingly, but the inductance was bang on at just over 109H. Change). The antennas are set up as a sloper as in my SOTA outings. Nothing drastic but likely the SWR on the summit will vary as conditions and the setup change. Being conservative, assume we are just 90% efficient, then the average power level we could support would be about 140W. Note the material 43 hysteresis curves shown below for 25 C and 100 C has a smaller open area (and hence lower losses) at the higher temperature. One end may even be close to the ground, not yielding the best radiation efficiency, but much activation proved it still operational. Ez az oldal az Akismet szolgltatst hasznlja a spam cskkentsre. To explore parameter space a little, I modeled a couple of lengths for the counterpoise and see how the wire is resonant across the band when fed with various impedances at the driven point. It is not necessary to calculate the above; the results are sown in the following table. The SWR for 30 meters, 1.05:1, was the lowest of all three antennas since the transformer was tuned for impedance match at 30 meters. With tension on the antenna wire, you can just roll the coil up/down the wire to try different positions as you are optimizing for a particular band. When I'm measuring the half way point on my EFHW, looking for 67', how do I factor in the compensation coil on the MyAntennas wire? Lets do a quick calculation to see how much an issue is this output capacitance. Apply for the Job in Software Engineer - EDI at St. Louis, MO. This will allow good matching of the half-wave radiating antenna wire to the 50 coaxial cable at virtually any location. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Enter your email address to subscribe to this blog and receive notifications of new posts by email. 2015. End Fed Half Wave Antenna Coupler Schematic - 7-30MHz. Why had I not noticed this before? Yes, there is a coil a few feet from the box but it is NOT TRAP, it is no secret as well, actually, everything in this antenna was published and patented by few people a long ago. Jos van den Helm's (PA1ZP) article published in Radcom: Fig.1 - Withdraw the radiating element carefully to avoid damaging the matching components A few years ago I bought a secondhand Diamond X50 dual band (144/430) antenna at a radio car boot sale. From this article one may build a 40, 30, 20m end fed half wave antenna, with no special parts needed, or no special skills required. Elnzst krnk, de elsikkadt az zenete. The following describes such a transformer using a Fair-rite 2643625002 core (16.257.2914.3mm #43). These four data points are plotted on the Transmission Losses chart shown below as the yellow squares, all but the 80 meter point coming in a bit lower than expected losses based on the VNA measurements. The following is the most up-to-date information related to EFHW Compensation Coil Experiment. As you look to use this transformer at higher power levels, I can imagine that the bottleneck might be voltage breakdown or corona in the windings. 3) Total losses are approximately independent of core volume. For our transformer at 100W (==> 71 Vrms into 50 ) , the core cross section for the two FT114s is 0.74 cm2 , consider the lowest frequency as 3.5 MHz and our 5-turn primary, then plugging in the numbers we find Bmax = 0.012 T. Lets consider a much more challenging extreme: 1000W and the 160m band. Wrap the first wire around the toroid 27 times (I used a black wire for this). What seemed to work best was to concentrate the turns on the tap-side of the secondary winding, using several (#28) wires in parallel for the primary turns such that they covered about half of the underlying secondary winding. <> The second smallest number I measured was 2.7pF, derived from the self resonance at 2.72 MHz with the magnetizing inductance (measured at 25.8 H) with the secondary open and the output wire folded to a small 1/2 length. HA5CBM Mikls, Finally the tank circuits specification is complete, which is sown below. Payment: If you are eligible, Crosswalk CAA will make the appropriate payment to your energy provider (s) on your behalf. This will yield the minimal capacitance of the variable capacitor. Copyright 2014-2023. A transformer was wound on a FT50-43 toroid with 3 bifilar turns followed by another 31 turns of #26 enameled magnetic wire. Note: If we change the primary number of turns, the impedance ratios will considerable change also. In an ideal setting, the center of the antenna will have the lowest voltage, consequently impedance, which is why it is possible to feed it by 50 or 75 coaxial cable. One cable is the coax feedline, the second is the supply to the cooling fan and control of relays. Im a hundred watt guy, so do not have a lot of experience with high voltage RF, but I know that ~5kV peak-to-peak RF voltage that you would expect at the 2450 output at kilowatt power levels could begin to cause you some trouble. The transformer was attached to the 30 meter EFHW antenna and turns were removed for best match to 50 ohms. It is not necessary to calculate the above; the results are sown in the following table. Because of the division of power between the 3220 resistor and VNA input, there is effectively an attenuator of -10*log(50/(50+3220))=18.16dB, so |S21| has a component due to this division. Best regards and thanks again for your comment. Make sure the first wire is wrapped evenly around the whole toroid. There's seemingly conflicting information out there, such as on QRZ the consensus seems to be to either use no choke on the coax, or choke it some ways away from the feedpoint - WA7ARK recommends .07 wavelength, which is about 9' on 40M. The previous table already contains these measurements. Will there be the same performance for single band EFHWs? I fashioned an antenna connector with washers made from some acrylic rod I had on hand. Firstly, lets estimate at 3.6MHz minimum number of turns to ensure that magnetising conductance is less than about 0.002S (for better than 90% core efficiency). After acquiring a MTR3b for SOTA activations I decided I needed a different antenna than the End Fed Random Wire (EFRW) or the speaker cable 20 meter dipole I use with my KX2. Thirty turns #28 are wound on the two FT114-43 cores. I hope to do more experiments with single and multi band EFHW antennas above 20 meters - stay tuned -- The experiments have been performed, check it out! An example is shown in this figure of a 49:1 transformer with a 100 pfd capacitor in the primary side of the transformer. (30 votes, Rating: 5.00) - Please vote the article with your valuable star rating. It is all about getting the heat out. Typical EFHW Antenna Characteristics & Performance, Influence on Performance due to Deployment Environment, Construction Variables and Transmission Line Interface, Optimum Counterpoise length and Coupling Transformer, Influence of EFHW wire orientation on performance, Good Antenna for any Radio Station is vital The importance of antennas for radio communications can never be over-emphasized. I found it very useful to label the tuner with switch and capacitance positions. The combination of the transformer with the end-fed dipole results in a positive reactance. These inductances are required in determining the right capacitance values, of which two values are important: the minimal and the maximum capacitance values. Basically, the loading coil is operating as a trap. Transmitting on 15 meters was impossible because of RF into the radio. For the antenna wire itself, I used 119 feet of 22g stranded hookup wire. Ha elolvasod alapszablyunkat s a benne lertakat elfogadod, akkor nincs ms teendd, mint a ha5kdr@ha5kdr.hu email-cmen, vagy egy klubnapon jelentkezni nlunk! Then I covered the coil in kapton tape to hold it together. I wish you lots of productive experimentations and successful portable operations. It may be one or even five kilo-ohms. I am building an EFHW antenna for my new. I used the 14g enameled wire and wound it on the FT240-43. So, I embarked on testing it for myself. With most operations you only transmit for 50% of the time, and since a small transformer with four or more primary turns can achieve >90% efficiency, that implies that I really only need to dissipate ~5W. If you really wanted to push this design, you could include thermal grease or thermal pads in the stack-up to improve the heat transfer, but I chose to keep it clean and see how it would do without any special effort. End Fed Half Wave (EFHW) Antenna Upgrade Part 1 - The Matching Transformer. 100W on a Wire Antenna How far would it reach? I suspect that a small coil near the transformer is generally a good idea, whether it is my transformer design or others, since it is very difficult to get the antenna wire out of the box without incurring some excess capacitance. Also find news related to Efhw Compensation Coil Experiment which is trending today. Below about 7 MHz, transmission losses increase as the core temperature increases. Thanks again Jim. The SWR results are as follows: Considering the compromised installation (ends about 2.5-3m above ground, inverted V with peak at 8m) I am pretty happy with this so far. The point is to get the characteristic time constant for the cooling, which is the reciprocal of the exponent coefficient that Excel shows for the fitting equation. This will allow good matching of the half-wave radiating antenna wire to the 50 coaxial cable at virtually any location. I was curious why this capacitor was added to the transformer. If the antenna is not tuned properly, and it represents other than 50, the diode will rectify the current flowing across the bridge and the LED will light up. Ive been wanting to get back into radio stuff for a while now, but the only antenna that I have up now is a 40 meter dipole. The SWR was low, but not unity, so the peak voltage was lower than the 50 ohm match value when measured with the high-Z scope probe. To calculate the impedance ratio, use the following equation: A completed tuner is shown here, which depicts the inductance assembly. In this case C~5pF and Z~2450 suggests that the inductance needed should be about 30 H. I decided to play with this to see what I could accomplish. Real end fed antennas operated harmonically do not present a constant impedance, not even in harmonically related bands. Measurements were made on the unmounted transformer with just a ~2 inch length of lead from the secondary to the 2450 load and sampling resistor (jig connections as shown in the photo above). This is indeed a classic antenna that is not only, Introduction to Omnidirectional Antennas In the literal sense, an Omnidirectional antenna is an antenna that radiates uniformly in all directions. Thanks in advance, good health for you in these times, Im not interested in trialing coil-loaded dipoles at the minute (from my limited reading bandwidth can be a real issue) so the options I like include: The G0KYA/PD7MAA/IK0IXI EFHW extension to cover 80m calls for a 110uH coil placed at the end of the EFHW, with a further 2-2.5m of wire beyond this. Calculate the capacity for the resonance at the lowest frequency to be covered with the lowest inductivity taken in consideration. One way or another there is always a counterpoise involved if the antenna is tuned correctly. RC = 2500 x 1.0e-12 = 2.5 nS Now consider the period of a 30 MHz wave. I needed to add an additional coil (approx 12.5 uH) about . It is basically an end fed half wave dipole on 20m/40m and an end fed full wave dipole on 10m. I set up an EFHW for field day using a similar transformer with 25 ft. of coax from the box, everything floating, to my battery powered radio. I recommend a good reading on this subject by Steve Yates, AA5TB at: www.aa5tb.com/efha.html. (Tvir s tvbeszl gpek s kszlkek) Ksznm. We also know, that both ends of the half wave antenna will have the highest voltage, thus impedance, which may reach up to several kilo-ohms. Once completed and tape-wrapped, I applied a layer of liquid electrical tape over the surface and the interior wire connections, ready to go outdoors. I then used a piece of heat shrink on the outside to hold everything in place. In case you need to perform calculations, use the formula: Where the frequency f is in MHz and the inductance L is in H. This article will describe a 40/30/20m band end-fed half wave antenna, focusing on its matching unit. This will also be handling 100W. Most informative and appreciated. From experience, I found that with this tuner my SWR was better by simply disconnecting the counterpoise at lower bands. In the open-box image above you can see the thermal probe I used to measure the ferrite core temperature for a thermal characterizations. Be aware counterpoise or ground radials are required for all hf antennas for better performance. ROB@COMCOIL.COM After doing some research on the internet I eventually came across something about rattling radiating elements in Diamond vertical ant, Once I had upgraded the matching transformer for my EF-10/20/40 MKII "EndFedz" (see Part 1) my thoughts turned to the loading coil. Adding an additional 2 meters to the counterpoise did very little to affect the resonant frequencies, much less than adding that length to the main wire would accomplish. Now I just need to build or acquire a decent radio to utilize this new antenna. Wow, Gary! Commercial Coils, Inc. 213 Chesterfield Industrial Blvd Chesterfield, Missouri 63005. Connected to the packaged transformer, I ran some SWR sweeps with just the bare wire and various configurations of small coils to act as band-tuning compensation. The smallest number I measured was 1.6 pF, derived from the self-resonance at 41 MHz with the leakage inductance (measured at 198 nH) when the secondary was shorted. I tried to operate from a hotel, and learned the hard way that this type of antenna is not suitable for such location. Inverted V Antenna A popular Dipole variant, EMI-RFI and Noise related HF Radio Station performance loss. The toroid with its many taps may be soldered directly on a multi-position switch. I also built one that is heavy-duty handling easily up to 100W for 80/60/40m bands. For fun, I attached an 18 clip lead to the secondary output and observed 7.2 pF due to the dangling clip lead. It uses a coil as a compensation unit, and no counterpoise. This graphical depiction makes it easier to visualize the current and impedance correlation between bands. It matches the impedance fairly well to the half-wave antennas high impedance at one of its ends. Having recently built a MTR2 3-band CW transceiver, I was keen to make band switching on a mountain top as simple as possible.

Francis Desouza Political Party, Mandeville Volleyball, Tetsuo Ted'' Ogawa Email Address, What Biome Is Miami, Florida, Magkano Ang Operasyon Sa Almoranas, Articles E